💰 Free Finance & Crypto Calculators
Three calculators for the numbers that are easy to get wrong in your head: what compounding actually does over ten years, what a trade returned once fees are counted, and what a given prompt costs across the major AI models. Estimates for planning — not financial advice.
Percentage Calculator
Percentage change, discounts, VAT, working backwards from a total, and what a headline return actually means per year.
Compound Growth & Crypto Staking Calculator
Project compound interest, savings growth, and crypto staking returns over time.
Crypto Profit & ROI Calculator
Calculate your crypto profit, loss, and ROI from buy and sell price, including trading fees.
AI Token & Cost Calculator
Estimate token count and input cost for your text across GPT-4o, Claude, and Gemini models.
How to get the most out of these
Three calculators, one shared principle: show the arithmetic people skip. Compounding is unintuitive over long spans, fees on both sides of a trade eat more than the headline suggests, and AI token costs only feel small until multiplied by a batch job. Each calculator makes the skipped step visible as a number.
Read all three the same way: the math is exact, the assumptions are not. The compound calculator holds a rate steady for years, which no market does; the crypto calculator models one clean trade without slippage or tax; the token calculator estimates tokens without the model's real tokenizer. The pages state their own gaps - use the results as planning sketches with known edges.
None of this is financial advice, and everything runs in your browser - amounts, trades, and prompts stay on your machine.