Exchange Rates

📋 Overview

Expense Tracker: Koala (“Koala”) supports multi-currency bills with exchange rate lookup and switching.

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💰 What is the base currency?

The base currency is the main currency of your ledger. It is used for:

• Displaying amounts across the app
• Calculations in overview and statistics
• Showing exchange rates relative to the base currency

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🚀 Change the base currency

Option 1: From Currency Settings

1. Open Expense Tracker: Koala and go to Settings
2. Tap Currency settings
3. Tap Base currency
4. Select a new currency

Koala will refresh exchange rates and update amount display.

Option 2: From Ledger Details

1. Open Ledger management
2. Open the ledger details
3. Tap Ledger currency
4. Select a new currency

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📊 Exchange rate list

You can:

• Browse supported currencies
• See rates relative to the base currency
• Tap the refresh button to fetch the latest rates

💡 Tip:

• Rates are fetched from the server via a third-party exchange-rate provider.
• When offline, Koala uses cached rates.

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💱 How exchange rates affect bills

• Koala converts amounts using the current exchange rate.
• If the exchange rate changes (for example after refresh), the converted display of historical bills may also change.
• The original transaction amount is not changed.

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🔄 Caching

Koala caches exchange rates to improve performance.

• Cache is updated when you refresh rates or change base currency or ledger currency.

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Last updated: May 2026