diff --git a/iosApp/iosApp/ContentView.swift b/iosApp/iosApp/ContentView.swift
index fc5ebe3..7c7f882 100644
--- a/iosApp/iosApp/ContentView.swift
+++ b/iosApp/iosApp/ContentView.swift
@@ -105,13 +105,22 @@ struct ContentView: View {
                     }
                 }
 
-                if !state.oneCurrencyToSats.isEmpty {
-                    HStack {
-                        Text(IosLocalizationKt.localizedFormattedString(
-                            resource: MR.strings.shared.currency_to_sats,
-                            args: [state.defaultCurrencyCode]
-                        ))
-                        Spacer()
+                HStack {
+                    Text(IosLocalizationKt.localizedFormattedString(
+                        resource: MR.strings.shared.currency_to_sats,
+                        args: [state.defaultCurrencyCode]
+                    ))
+                    Spacer()
+                    if state.isManualSource {
+                        NumericField(
+                            placeholder: "",
+                            value: state.manualSatsPerCurrencyInput,
+                            keyboardType: .decimalPad,
+                            sanitize: sanitizeDecimalInput,
+                            onChange: { viewModel.onManualSatsPerCurrencyChanged($0) },
+                            alignment: .trailing
+                        )
+                    } else if !state.oneCurrencyToSats.isEmpty {
                         Text(NumberFormatKt.groupDigits(value: state.oneCurrencyToSats))
                     }
                 }
diff --git a/iosApp/iosApp/ConverterViewModel.swift b/iosApp/iosApp/ConverterViewModel.swift
index 5ccb7f9..9fb7370 100644
--- a/iosApp/iosApp/ConverterViewModel.swift
+++ b/iosApp/iosApp/ConverterViewModel.swift
@@ -46,4 +46,8 @@ final class ConverterViewModel: ObservableObject {
     func onManualRateChanged(_ value: String) {
         bridge.onManualRateChanged(value: value)
     }
+
+    func onManualSatsPerCurrencyChanged(_ value: String) {
+        bridge.onManualSatsPerCurrencyChanged(value: value)
+    }
 }
diff --git a/shared/src/appleMain/kotlin/xyz/tyiu/satsprice/IosPriceViewModel.kt b/shared/src/appleMain/kotlin/xyz/tyiu/satsprice/IosPriceViewModel.kt
index 13e7a31..1db6127 100644
--- a/shared/src/appleMain/kotlin/xyz/tyiu/satsprice/IosPriceViewModel.kt
+++ b/shared/src/appleMain/kotlin/xyz/tyiu/satsprice/IosPriceViewModel.kt
@@ -31,6 +31,7 @@ data class IosConverterState(
     val sourceName: String,
     val isManualSource: Boolean,
     val manualRateInput: String,
+    val manualSatsPerCurrencyInput: String,
     val isLoading: Boolean,
     val errorMessage: String?,
     val statusLine: String,
@@ -64,6 +65,7 @@ class IosPriceViewModel {
     fun onFiatCurrenciesReordered(newOrder: List<String>) = viewModel.onFiatCurrenciesReordered(newOrder)
     fun onSourceSelected(name: String) = viewModel.onSourceSelected(name)
     fun onManualRateChanged(value: String) = viewModel.onManualRateChanged(value)
+    fun onManualSatsPerCurrencyChanged(value: String) = viewModel.onManualSatsPerCurrencyChanged(value)
 }
 
 private fun ConverterUiState.toIosState(): IosConverterState = IosConverterState(
@@ -83,6 +85,7 @@ private fun ConverterUiState.toIosState(): IosConverterState = IosConverterState
     sourceName = sourceName,
     isManualSource = isManualSource,
     manualRateInput = manualRateInput,
+    manualSatsPerCurrencyInput = manualSatsPerCurrencyInput,
     isLoading = isLoading,
     errorMessage = errorMessage,
     statusLine = statusLine(),
diff --git a/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceScreen.kt b/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceScreen.kt
index c949f2e..5f7c875 100644
--- a/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceScreen.kt
+++ b/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceScreen.kt
@@ -209,12 +209,23 @@ fun PriceScreen(
                         }
                     }
 
-                    val oneCurrencyToSats = state.oneCurrencyToSats()
-                    if (oneCurrencyToSats.isNotEmpty()) {
+                    if (state.isManualSource) {
+                        OutlinedTextField(
+                            value = state.manualSatsPerCurrencyInput,
+                            onValueChange = viewModel::onManualSatsPerCurrencyChanged,
+                            label = { Text(stringResource(MR.strings.currency_to_sats, state.defaultCurrencyCode)) },
+                            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                            singleLine = true,
+                            visualTransformation = DigitGroupingTransformation,
+                            modifier = Modifier.fillMaxWidth(),
+                        )
+                    } else {
+                        val oneCurrencyToSats = state.oneCurrencyToSats()
                         OutlinedTextField(
                             value = oneCurrencyToSats,
                             onValueChange = {},
                             readOnly = true,
+                            enabled = oneCurrencyToSats.isNotEmpty(),
                             label = { Text(stringResource(MR.strings.currency_to_sats, state.defaultCurrencyCode)) },
                             singleLine = true,
                             visualTransformation = DigitGroupingTransformation,
diff --git a/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceViewModel.kt b/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceViewModel.kt
index b0fd052..eda76ce 100644
--- a/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceViewModel.kt
+++ b/shared/src/commonMain/kotlin/xyz/tyiu/satsprice/ui/PriceViewModel.kt
@@ -50,6 +50,7 @@ data class ConverterUiState(
     val sourceName: String = "",
     val isManualSource: Boolean = false,
     val manualRateInput: String = "",
+    val manualSatsPerCurrencyInput: String = "",
     val isLoading: Boolean = true,
     val errorMessage: String? = null,
     val lastUpdated: Instant? = null,
@@ -239,7 +240,12 @@ class PriceViewModel(
                 if (seedRate != null) {
                     manualSource.rate = seedRate
                     _uiState.update {
-                        it.copy(manualRateInput = formatAmount(seedRate, decimalDigitsFor(defaultCurrencyCode)))
+                        it.copy(
+                            manualRateInput = formatAmount(seedRate, decimalDigitsFor(defaultCurrencyCode)),
+                            manualSatsPerCurrencyInput = CurrencyConverter.satsPerCurrencyUnit(seedRate)
+                                ?.let { sats -> formatAmount(sats, 0) }
+                                .orEmpty(),
+                        )
                     }
                 }
                 refresh()
@@ -260,13 +266,41 @@ class PriceViewModel(
             exchangeRateStore.loadLastKnownRates(source.id)?.rates?.get(defaultCurrencyCode)
         }
 
+    /**
+     * The "BTC to [defaultCurrencyCode]" and "[defaultCurrencyCode] to Sats" fields edit the same
+     * underlying [ManualExchangeRateSource.rate] from two different angles — entering one always
+     * recomputes the other, via the same self-inverse division ([CurrencyConverter.satsPerCurrencyUnit]
+     * of a rate is a Sats amount, and of a Sats amount is a rate).
+     */
     fun onManualRateChanged(value: String) {
         val sanitized = sanitizeDecimalInput(value)
-        _uiState.update { it.copy(manualRateInput = sanitized) }
         // Also cleared (rather than left as the last valid rate) when sanitized fails to parse —
         // e.g. the field is emptied, or is mid-edit on an incomplete number — so refresh() then
         // wipes any fiat amounts computed from it, rather than leaving stale ones on screen.
-        manualSource.rate = sanitized.toBigDecimalOrNull()
+        val parsed = sanitized.toBigDecimalOrNull()
+        manualSource.rate = parsed
+        _uiState.update {
+            it.copy(
+                manualRateInput = sanitized,
+                manualSatsPerCurrencyInput = parsed?.let { rate -> CurrencyConverter.satsPerCurrencyUnit(rate) }
+                    ?.let { sats -> formatAmount(sats, 0) }
+                    .orEmpty(),
+            )
+        }
+        refresh()
+    }
+
+    fun onManualSatsPerCurrencyChanged(value: String) {
+        val sanitized = sanitizeDecimalInput(value)
+        val parsedSats = sanitized.toBigDecimalOrNull()
+        val rate = parsedSats?.let { sats -> CurrencyConverter.satsPerCurrencyUnit(sats) }
+        manualSource.rate = rate
+        _uiState.update {
+            it.copy(
+                manualSatsPerCurrencyInput = sanitized,
+                manualRateInput = rate?.let { formatAmount(it, decimalDigitsFor(defaultCurrencyCode)) }.orEmpty(),
+            )
+        }
         refresh()
     }