Currencies & Exchange Rates

Kalc provides complete currency conversion and monetary calculations, supporting over 170 ISO fiat currencies and major cryptocurrencies (Bitcoin, Ethereum, Solana) with offline caching and arbitrary-precision decimal evaluation.

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Supported Currencies & Symbols

You can express currencies using standard three-letter ISO 4217 codes or common currency symbols:

100 USD in EUR                                  // 92.17 EUR
50 GBP in JPY                                   // 9,650 JPY
1.5 BTC in USD                                  // $97,500.00
25 SOL in EUR                                   // 3,250.00 EUR

Symbol Placement Flexibility

Kalc supports both leading and trailing currency notation according to your regional convention:

• Prefix Notation: $150.00, €120, £45, ¥5,000
• Postfix Notation: 150 USD, 120 EUR, 45 GBP, 5000 JPY

Minor Currency Units

Common minor units are recognized automatically:

• cents / c: $5 50 cents $\to$ $5.50
• pence / p: £2 80p $\to$ £2.80

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Mixed-Currency Arithmetic

Combine and convert mixed currencies in a single expression:

hotel = 450 EUR
flight = $620
meals = £180
total_spend = (hotel + flight + meals) in USD   // $1,338.45

When summing mixed currencies without an explicit in <Currency> target, Kalc converts the sum into your active Default Currency (configured in Preferences):

$100 + 50 EUR                                   // $154.25 (when USD is default)

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Offline-First Architecture & Rate Caching

Unlike browser calculators that stall or show errors when you are offline, Kalc is designed for complete travel resilience:

1. Local Bundled Store: Kalc includes an offline database of cross-rates referenced to USD.
2. Background Sync: When connected to the internet, ExchangeRateStore refreshes rates quietly in the background at your preferred interval (e.g., every 6 or 24 hours).
3. Freshness Badge: The header bar displays a subtle live status pill:
   • Live: Rates updated recently.
   • 3h ago: Elapsed duration since last refresh.
   • Offline: Operating in cached offline mode.
4. Zero Third-Party Leaks: Rate refreshes query reliable financial feeds without transmitting your personal calculation content or IP metadata.

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Historical Inflation & Deflation (CPI)

Kalc embeds the historical US Consumer Price Index (CPI) tables, allowing you to compute historical monetary purchasing power over the past century:

1. Deflating Modern Money to Past Values

Determine what a modern dollar amount would have been worth in an earlier year:

what was $500 worth in 1997                     // $249.27
what was $100 worth in 1980                     // $25.59
what was $1,000 worth in 1970                   // $120.50

2. Inflating Historical Money to Modern Values

Determine what historical money equates to in today's purchasing power:

$1 from 1997 today                              // $2.01
$100 from 1980 today                            // $390.78
$25,000 from 1990 today                         // $61,591.43
House bought for $85,000 from 1980 today        // $332,160.19

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Currency Preferences (⌘ ,)

In Preferences > Calculations:

• Default Currency: Choose your primary currency (USD, EUR, GBP, CHF, CAD, AUD, JPY, etc.).
• Symbol Position: Choose whether symbols render before ($10) or after (10$).
• Grouping Separator: Format large amounts with commas ($1,000,000), dots (1.000.000 €), or spaces (1 000 000 €).
• Decimal Separator: Choose period (.) or comma (,).