What is CoinTaxKit - free crypto tax calculators & CSV analyzer?
CoinTaxKit is a free collection of browser-based calculators for crypto investors who want to understand their tax position before paying for software or an accountant. Instead of one monolithic app, it's a set of small tools that each do one job well: estimate capital gains, compare cost basis methods, classify holding periods, total up exchange fees, value staking and mining income, check whether something is a taxable event, and preview disposals in a Form 8949-style table.
Built around your real data
The centerpiece is the Capital Gains & Cost Basis Calculator, where you can enter transactions manually or upload an exchange CSV and see your gains computed under FIFO, LIFO, and HIFO side by side - split into short-term and long-term, with estimated tax at rates you set, tax-loss harvesting candidates from your remaining holdings, and a downloadable report. The CSV Transaction Analyzer takes the same exchange exports and summarizes them into buys, sales, transfers, fees, and income, so you know what you're dealing with before tax season starts.
Private by design
Every calculator runs entirely in your browser. There's no account to create, nothing to install, and no server receiving your data - CSV files are parsed locally on the page and your transaction history never leaves your device. That makes these tools a safe first step: explore your numbers freely, then decide whether you need full-service software.
Free tools, honest limits
Everything here is an estimate, not tax advice. The calculators use simplified rules - a one-year holding threshold, flat rates you choose, no wash-sale logic - and every results page says so plainly. When you're ready to file, the Tax Software Finder points you to full platforms like Koinly, CoinTracker, and CoinLedger (some links are affiliate links, always disclosed), and for anything beyond an estimate, a qualified tax professional should have the final word.