Tools

Financial and Betting Calculators

Free tools for investing and financial independence, and for getting the most out of bookmaker bonuses.

Investment calculators

Compound Interest Calculator

Calculate your investment growth over time with nominal and real inflation-adjusted returns and IRPF 2026 tax impact.

FIRE Calculator

Calculate your FIRE number (4% rule) and the years you need to reach financial independence. Includes Spanish public pension.

Matched Betting Calculator

Calculate the optimal lay stake for any matched betting bet. Sport-neutral result, guaranteed profit.

Surebets Calculator

Calculate stakes for arbitrage between two or more bookmakers with guaranteed profit regardless of outcome.

Sequential Calculator

Manage your betting sequence to meet a bonus rollover with minimum loss and controlled exposure.

No-Lay Promos Calculator

Calculate the expected value of no-lay promos (no exchange): free bets, odds boosts and cashback with exact EV calculation.