diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreen.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreen.kt
index ab57272..e666c0b 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreen.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreen.kt
@@ -13,6 +13,7 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.heightIn
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.grid.GridCells
@@ -29,6 +30,7 @@ import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.LocalContentColor
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ModalDrawerSheet
 import androidx.compose.material3.ModalNavigationDrawer
@@ -269,15 +271,33 @@ private fun ErrorDialog(message: String, onDismiss: () -> Unit) {
     )
 }
 
+internal const val CalculatorDialogTag = "calculator_dialog"
 internal const val CalculatorSummaryTag = "calculator_summary"
 internal const val CalculatorAccountButtonTag = "calculator_account_button"
 internal const val AccountResultConfirmButtonTag = "account_result_confirm_button"
+internal const val AccountResultProgressTag = "account_result_progress"
 
 private val DialogMaxWidth = 720.dp
+private val DialogPadding = 24.dp
 private val NumberPadMaxWidth = 360.dp
+private val NumberPadMinWidth = 156.dp
 private val TwoPaneMinWidth = 600.dp
 private val KeyGap = 4.dp
 private val AmountSafetyMargin = 8.dp
+private val SummaryGapHeight = 40.dp
+private val PaneGap = 24.dp
+private val ProgressIndicatorSize = 24.dp
+private const val NumberPadRows = 4
+private const val NumberPadColumns = 3
+private const val AmountBlockCount = 3
+private const val SinglePaneSummaryRatio = 0.45f
+
+// 高さが足りない端末では横幅ではなく高さがキーの大きさを決める
+private fun fittingPadWidth(availableWidth: Dp, availableHeight: Dp): Dp {
+    val byWidth = min(availableWidth, NumberPadMaxWidth)
+    val byHeight = availableHeight * (NumberPadColumns.toFloat() / NumberPadRows)
+    return min(byWidth, byHeight).coerceAtLeast(min(NumberPadMinWidth, byWidth))
+}
 
 // タブレットでも文字が切れないよう、実測して収まる最大のスタイルを選ぶ
 @Composable
@@ -292,6 +312,32 @@ private fun fittingStyle(samples: List<String>, candidates: List<TextStyle>, max
     } ?: candidates.last()
 }
 
+// 横幅だけでなく、3段の金額とラベルが縦にも収まるスタイルを選ぶ
+@Composable
+private fun fittingAmountStyle(
+    samples: List<String>,
+    candidates: List<TextStyle>,
+    maxWidth: Dp,
+    maxHeight: Dp
+): TextStyle {
+    val measurer = rememberTextMeasurer()
+    val density = LocalDensity.current
+    val maxWidthPx = with(density) { maxWidth.coerceAtLeast(0.dp).toPx() }
+    val labelsHeightPx = measurer
+        .measure(text = "0", style = MaterialTheme.typography.titleMedium, maxLines = 1)
+        .size.height * AmountBlockCount
+    val amountBudgetPx = with(density) {
+        (maxHeight - SummaryGapHeight).coerceAtLeast(0.dp).toPx()
+    } - labelsHeightPx
+    return candidates.firstOrNull { style ->
+        val measured = samples.map {
+            measurer.measure(text = it, style = style, softWrap = false, maxLines = 1)
+        }
+        measured.all { it.size.width <= maxWidthPx } &&
+            measured.maxOf { it.size.height } * AmountBlockCount <= amountBudgetPx
+    } ?: candidates.last()
+}
+
 @Composable
 private fun amountStyleCandidates(): List<TextStyle> {
     val typography = MaterialTheme.typography
@@ -319,50 +365,63 @@ private fun CalculatorDialog(
     ) {
         BoxWithConstraints(modifier = Modifier.padding(16.dp)) {
             val contentWidth = min(maxWidth, DialogMaxWidth)
-            val innerWidth = contentWidth - 48.dp
+            val availableHeight = maxHeight
+            val innerWidth = contentWidth - DialogPadding * 2
             val twoPane = contentWidth >= TwoPaneMinWidth
-            val padWidth = min(innerWidth, NumberPadMaxWidth)
-            val summaryWidth = if (twoPane) innerWidth - padWidth - 24.dp else innerWidth
 
             Surface(
                 shape = MaterialTheme.shapes.medium,
-                modifier = Modifier.width(contentWidth)
+                modifier = Modifier
+                    .width(contentWidth)
+                    .heightIn(max = availableHeight)
+                    .testTag(CalculatorDialogTag)
             ) {
-                Column(
-                    modifier = Modifier
-                        .padding(24.dp)
-                        .verticalScroll(rememberScrollState())
-                ) {
-                    if (twoPane) {
-                        Row(modifier = Modifier.fillMaxWidth()) {
-                            CalculatorSummary(
-                                state = state,
-                                maxWidth = summaryWidth,
-                                modifier = Modifier.width(summaryWidth)
-                            )
-                            Spacer(modifier = Modifier.width(24.dp))
-                            NumberPad(
-                                onNumber = onNumber,
-                                onClear = onClear,
-                                modifier = Modifier.width(padWidth)
-                            )
+                Column(modifier = Modifier.padding(DialogPadding)) {
+                    // フッターを先に測らせ、その残りの高さでキーパッドの大きさを決める
+                    BoxWithConstraints(modifier = Modifier.weight(1f, fill = false)) {
+                        val bodyHeight = maxHeight
+                        Column(modifier = Modifier.verticalScroll(rememberScrollState())) {
+                            if (twoPane) {
+                                val padWidth = fittingPadWidth(innerWidth - PaneGap, bodyHeight)
+                                val summaryWidth = innerWidth - padWidth - PaneGap
+                                Row(modifier = Modifier.fillMaxWidth()) {
+                                    CalculatorSummary(
+                                        state = state,
+                                        maxWidth = summaryWidth,
+                                        maxHeight = bodyHeight,
+                                        modifier = Modifier.width(summaryWidth)
+                                    )
+                                    Spacer(modifier = Modifier.width(PaneGap))
+                                    NumberPad(
+                                        onNumber = onNumber,
+                                        onClear = onClear,
+                                        modifier = Modifier.width(padWidth)
+                                    )
+                                }
+                            } else {
+                                val summaryHeight = bodyHeight * SinglePaneSummaryRatio
+                                CalculatorSummary(
+                                    state = state,
+                                    maxWidth = innerWidth,
+                                    maxHeight = summaryHeight,
+                                    modifier = Modifier.fillMaxWidth()
+                                )
+                                Spacer(modifier = Modifier.padding(12.dp))
+                                NumberPad(
+                                    onNumber = onNumber,
+                                    onClear = onClear,
+                                    modifier = Modifier
+                                        .width(
+                                            fittingPadWidth(
+                                                innerWidth,
+                                                bodyHeight - summaryHeight - PaneGap
+                                            )
+                                        ).align(Alignment.CenterHorizontally)
+                                )
+                            }
                         }
-                    } else {
-                        CalculatorSummary(
-                            state = state,
-                            maxWidth = summaryWidth,
-                            modifier = Modifier.fillMaxWidth()
-                        )
-                        Spacer(modifier = Modifier.padding(12.dp))
-                        NumberPad(
-                            onNumber = onNumber,
-                            onClear = onClear,
-                            modifier = Modifier
-                                .width(padWidth)
-                                .align(Alignment.CenterHorizontally)
-                        )
                     }
-                    Spacer(modifier = Modifier.padding(10.dp))
+                    Spacer(modifier = Modifier.padding(8.dp))
                     HorizontalDivider()
                     Spacer(modifier = Modifier.padding(8.dp))
                     Row(
@@ -400,7 +459,12 @@ private fun CalculatorDialog(
 }
 
 @Composable
-private fun CalculatorSummary(state: CalculatorState, maxWidth: Dp, modifier: Modifier = Modifier) {
+private fun CalculatorSummary(
+    state: CalculatorState,
+    maxWidth: Dp,
+    maxHeight: Dp,
+    modifier: Modifier = Modifier
+) {
     val remaining = state.deposit - state.totalPrice
     val totalText = stringResource(R.string.river_format, state.totalPrice)
     val depositText = stringResource(R.string.river_format, state.deposit)
@@ -408,10 +472,11 @@ private fun CalculatorSummary(state: CalculatorState, maxWidth: Dp, modifier: Mo
         R.string.river_format,
         if (remaining >= 0) remaining else -remaining
     )
-    val amountStyle = fittingStyle(
+    val amountStyle = fittingAmountStyle(
         samples = listOf(totalText, depositText, remainingText),
         candidates = amountStyleCandidates(),
-        maxWidth = maxWidth - AmountSafetyMargin
+        maxWidth = maxWidth - AmountSafetyMargin,
+        maxHeight = maxHeight
     )
     val onSurface = MaterialTheme.colorScheme.onSurface
 
@@ -561,6 +626,7 @@ private fun AccountResultDialog(
         BoxWithConstraints(modifier = Modifier.padding(16.dp)) {
             val typography = MaterialTheme.typography
             val contentWidth = min(maxWidth, DialogMaxWidth)
+            val availableHeight = maxHeight
             val changeText = stringResource(R.string.river_format, state.change)
             val changeStyle = fittingStyle(
                 samples = listOf(changeText),
@@ -577,39 +643,43 @@ private fun AccountResultDialog(
 
             Surface(
                 shape = MaterialTheme.shapes.medium,
-                modifier = Modifier.width(contentWidth)
+                modifier = Modifier
+                    .width(contentWidth)
+                    .heightIn(max = availableHeight)
             ) {
-                Column(
-                    modifier = Modifier
-                        .padding(32.dp)
-                        .verticalScroll(rememberScrollState()),
-                    horizontalAlignment = Alignment.CenterHorizontally
-                ) {
-                    Text(
-                        text = stringResource(R.string.change),
-                        style = typography.headlineMedium,
-                        maxLines = 1
-                    )
-                    Spacer(modifier = Modifier.padding(4.dp))
-                    Text(
-                        text = changeText,
-                        style = changeStyle,
-                        color = MaterialTheme.colorScheme.primary,
-                        maxLines = 1,
-                        softWrap = false,
-                        overflow = TextOverflow.Clip
-                    )
-                    Spacer(modifier = Modifier.padding(10.dp))
-                    HorizontalDivider()
-                    Spacer(modifier = Modifier.padding(6.dp))
-                    ResultSummaryRow(
-                        label = stringResource(R.string.total),
-                        amount = stringResource(R.string.river_format, state.totalPrice)
-                    )
-                    ResultSummaryRow(
-                        label = stringResource(R.string.deposit),
-                        amount = stringResource(R.string.river_format, state.deposit)
-                    )
+                Column(modifier = Modifier.padding(32.dp)) {
+                    Column(
+                        modifier = Modifier
+                            .weight(1f, fill = false)
+                            .verticalScroll(rememberScrollState()),
+                        horizontalAlignment = Alignment.CenterHorizontally
+                    ) {
+                        Text(
+                            text = stringResource(R.string.change),
+                            style = typography.headlineMedium,
+                            maxLines = 1
+                        )
+                        Spacer(modifier = Modifier.padding(4.dp))
+                        Text(
+                            text = changeText,
+                            style = changeStyle,
+                            color = MaterialTheme.colorScheme.primary,
+                            maxLines = 1,
+                            softWrap = false,
+                            overflow = TextOverflow.Clip
+                        )
+                        Spacer(modifier = Modifier.padding(10.dp))
+                        HorizontalDivider()
+                        Spacer(modifier = Modifier.padding(6.dp))
+                        ResultSummaryRow(
+                            label = stringResource(R.string.total),
+                            amount = stringResource(R.string.river_format, state.totalPrice)
+                        )
+                        ResultSummaryRow(
+                            label = stringResource(R.string.deposit),
+                            amount = stringResource(R.string.river_format, state.deposit)
+                        )
+                    }
                     Spacer(modifier = Modifier.padding(10.dp))
                     Row(
                         modifier = Modifier.fillMaxWidth(),
@@ -618,6 +688,7 @@ private fun AccountResultDialog(
                     ) {
                         TextButton(
                             onClick = onBack,
+                            enabled = !state.processing,
                             contentPadding = PaddingValues(horizontal = 24.dp, vertical = 16.dp)
                         ) {
                             Text(
@@ -628,9 +699,20 @@ private fun AccountResultDialog(
                         }
                         Button(
                             onClick = onOk,
+                            enabled = !state.processing,
                             contentPadding = PaddingValues(horizontal = 40.dp, vertical = 16.dp),
                             modifier = Modifier.testTag(AccountResultConfirmButtonTag)
                         ) {
+                            if (state.processing) {
+                                CircularProgressIndicator(
+                                    strokeWidth = 3.dp,
+                                    color = LocalContentColor.current,
+                                    modifier = Modifier
+                                        .size(ProgressIndicatorSize)
+                                        .testTag(AccountResultProgressTag)
+                                )
+                                Spacer(modifier = Modifier.width(12.dp))
+                            }
                             Text(
                                 text = stringResource(R.string.account),
                                 style = typography.headlineSmall,
diff --git a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt
index 794f652..ad68e6f 100644
--- a/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt
+++ b/app/src/main/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModel.kt
@@ -54,7 +54,8 @@ data class CalculatorState(
 
 data class AccountResultState(
     val totalPrice: Int,
-    val deposit: Int
+    val deposit: Int,
+    val processing: Boolean = false
 ) {
     val change: Int get() = deposit - totalPrice
 }
@@ -194,6 +195,7 @@ class MainViewModel @Inject constructor(
 
     fun onAccountResultBack() {
         val result = _uiState.value.accountResult ?: return
+        if (result.processing) return
         _uiState.update {
             it.copy(
                 accountResult = null,
@@ -205,6 +207,7 @@ class MainViewModel @Inject constructor(
     fun onAccountResultOk() {
         val state = _uiState.value
         val result = state.accountResult ?: return
+        if (result.processing) return
         if (state.mode == Mode.PRACTICE) {
             _uiState.update {
                 it.copy(
@@ -216,6 +219,7 @@ class MainViewModel @Inject constructor(
             }
             return
         }
+        _uiState.update { it.copy(accountResult = result.copy(processing = true)) }
         viewModelScope.launch {
             try {
                 saleRepository.createSale(
@@ -230,10 +234,11 @@ class MainViewModel @Inject constructor(
                 Timber.e(e, "createSale failed")
                 val message = e.localizedMessage
                 _uiState.update {
+                    val restored = it.copy(accountResult = result.copy(processing = false))
                     if (message != null) {
-                        it.copy(errorMessage = message)
+                        restored.copy(errorMessage = message)
                     } else {
-                        it.copy(errorMessageRes = R.string.network_error)
+                        restored.copy(errorMessageRes = R.string.network_error)
                     }
                 }
             }
diff --git a/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreenTest.kt b/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreenTest.kt
index d7ee77f..134a9a9 100644
--- a/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreenTest.kt
+++ b/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainScreenTest.kt
@@ -26,8 +26,11 @@ import info.nukoneko.cuc.android.kidspos.testutil.fakeSettingsRepository
 import info.nukoneko.cuc.android.kidspos.ui.barcode.BarcodeEventBus
 import info.nukoneko.cuc.android.kidspos.ui.barcode.BarcodeInput
 import info.nukoneko.cuc.android.kidspos.util.BarcodeKind
+import info.nukoneko.cuc.android.kidspos.util.Mode
 import java.io.IOException
 import kotlin.math.abs
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.runBlocking
 import org.junit.Assert.assertTrue
 import org.junit.Rule
 import org.junit.Test
@@ -228,6 +231,74 @@ class MainScreenTest {
         )
     }
 
+    @Test
+    @Config(qualifiers = "w960dp-h600dp-land-xhdpi")
+    fun calculatorFitsInsideNexus7Landscape() {
+        assertCalculatorFitsIn(600f)
+    }
+
+    @Test
+    @Config(qualifiers = "w360dp-h640dp-port-xhdpi")
+    fun calculatorFitsInsideSmallPhonePortrait() {
+        assertCalculatorFitsIn(640f)
+    }
+
+    @Test
+    fun accountResultShowsProgressWhileSaleIsInFlight() {
+        val gate = CompletableDeferred<Unit>()
+        val defaultCreateSale = apiService.createSaleHandler
+        apiService.createSaleHandler = { args ->
+            gate.await()
+            defaultCreateSale(args)
+        }
+        runBlocking { settingsRepository.setRunningMode(Mode.PRODUCTION) }
+        openCalculator()
+
+        pressKeys("5", "0", "0")
+        composeRule.onNodeWithTag(CalculatorAccountButtonTag).performClick()
+        composeRule.waitForIdle()
+        composeRule.onNodeWithTag(AccountResultProgressTag).assertDoesNotExist()
+
+        // ぐるぐるは終わらないアニメーションのため、waitForIdle が止まらなくなる
+        composeRule.mainClock.autoAdvance = false
+        composeRule.onNodeWithTag(AccountResultConfirmButtonTag).performClick()
+        composeRule.mainClock.advanceTimeBy(FRAME_STEP_MILLIS)
+
+        composeRule.onNodeWithTag(AccountResultProgressTag).assertIsDisplayed()
+        composeRule.onNodeWithTag(AccountResultConfirmButtonTag).assertIsNotEnabled()
+
+        gate.complete(Unit)
+        composeRule.mainClock.advanceTimeBy(FRAME_STEP_MILLIS)
+        composeRule.mainClock.autoAdvance = true
+        composeRule.waitForIdle()
+
+        composeRule.onNodeWithTag(AccountResultProgressTag).assertDoesNotExist()
+        composeRule.onNodeWithTag(AccountResultConfirmButtonTag).assertDoesNotExist()
+    }
+
+    private fun assertCalculatorFitsIn(screenHeight: Float) {
+        openCalculator()
+        pressKeys("5", "0", "0")
+
+        val dialog = composeRule.onNodeWithTag(CalculatorDialogTag).getUnclippedBoundsInRoot()
+        assertTrue(
+            "ダイアログが画面からはみ出している: ${dialog.height.value} / $screenHeight",
+            dialog.height.value <= screenHeight
+        )
+
+        val footer = composeRule.onNodeWithTag(CalculatorAccountButtonTag)
+            .getUnclippedBoundsInRoot()
+        assertTrue(
+            "かいけいボタンがダイアログの外にある: ${footer.bottom.value} / ${dialog.bottom.value}",
+            footer.bottom.value <= dialog.bottom.value + 1f
+        )
+
+        composeRule.onNodeWithTag(CalculatorAccountButtonTag).assertIsDisplayed()
+        composeRule.onNodeWithText(context.getString(R.string.back)).assertIsDisplayed()
+        composeRule.onNodeWithText("0").assertIsDisplayed()
+        composeRule.onNodeWithText(context.getString(R.string.delete)).assertIsDisplayed()
+    }
+
     private fun pressKeys(vararg keys: String) {
         keys.forEach { key ->
             composeRule.onNodeWithText(key).assertIsDisplayed().performClick()
@@ -276,4 +347,8 @@ class MainScreenTest {
 
         composeRule.onNodeWithText("復活商品").assertIsDisplayed()
     }
+
+    private companion object {
+        const val FRAME_STEP_MILLIS = 100L
+    }
 }
diff --git a/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModelTest.kt b/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModelTest.kt
index 3e0a94c..aa36155 100644
--- a/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModelTest.kt
+++ b/app/src/testProd/kotlin/info/nukoneko/cuc/android/kidspos/ui/main/MainViewModelTest.kt
@@ -14,6 +14,7 @@ import info.nukoneko.cuc.android.kidspos.ui.barcode.BarcodeEventBus
 import info.nukoneko.cuc.android.kidspos.ui.barcode.BarcodeInput
 import info.nukoneko.cuc.android.kidspos.util.BarcodeKind
 import info.nukoneko.cuc.android.kidspos.util.Mode
+import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.test.runTest
 import org.junit.Assert.assertEquals
@@ -260,6 +261,63 @@ class MainViewModelTest {
 
         assertEquals("boom", viewModel.uiState.value.errorMessage)
         assertFalse(viewModel.uiState.value.items.isEmpty())
+        assertEquals(false, viewModel.uiState.value.accountResult?.processing)
+    }
+
+    @Test
+    fun accountResultStaysProcessingUntilSaleCompletes() = runTest {
+        val gate = CompletableDeferred<Unit>()
+        val defaultCreateSale = apiService.createSaleHandler
+        apiService.createSaleHandler = { args ->
+            gate.await()
+            defaultCreateSale(args)
+        }
+        apiService.getItemHandler = { barcode ->
+            Item(id = 9, barcode = barcode, name = "item", price = 300, storeId = 1, genreId = 1)
+        }
+        settingsRepository.setRunningMode(Mode.PRODUCTION)
+        val viewModel = createViewModel()
+        emitBarcode("1001000001", BarcodeKind.ITEM)
+        viewModel.onAccountClick()
+        viewModel.enterDeposit(5, 0, 0)
+        viewModel.onCalculatorOk()
+
+        viewModel.onAccountResultOk()
+
+        assertEquals(true, viewModel.uiState.value.accountResult?.processing)
+
+        viewModel.onAccountResultOk()
+        viewModel.onAccountResultBack()
+
+        assertEquals(1, apiService.createSaleCalls.size)
+        assertEquals(true, viewModel.uiState.value.accountResult?.processing)
+
+        gate.complete(Unit)
+
+        assertNull(viewModel.uiState.value.accountResult)
+        assertTrue(viewModel.uiState.value.items.isEmpty())
+    }
+
+    @Test
+    fun accountResultStopsProcessingWhenSaleFails() = runTest {
+        apiService.createSaleHandler = { throw RuntimeException("boom") }
+        apiService.getItemHandler = { barcode ->
+            Item(id = 9, barcode = barcode, name = "item", price = 300, storeId = 1, genreId = 1)
+        }
+        settingsRepository.setRunningMode(Mode.PRODUCTION)
+        val viewModel = createViewModel()
+        emitBarcode("1001000001", BarcodeKind.ITEM)
+        viewModel.onAccountClick()
+        viewModel.enterDeposit(5, 0, 0)
+        viewModel.onCalculatorOk()
+
+        viewModel.onAccountResultOk()
+
+        assertEquals(false, viewModel.uiState.value.accountResult?.processing)
+
+        viewModel.onAccountResultOk()
+
+        assertEquals(2, apiService.createSaleCalls.size)
     }
 
     @Test