The Regret Calculator quantifies the cost of a past Bitcoin sale. Pick the date you sold, how much, and what you bought with it, and it shows three things: the capital-gains tax you paid, the appreciation you gave up as BTC rose, and how the purchase itself depreciated — versus what borrowing the same cash against your Bitcoin would have cost.
It uses real historical Bitcoin prices and is built to be shared. Free, no signup, runs entirely in your browser.
Three parts: the capital-gains tax you paid at sale, the appreciation you missed (what those coins would be worth today minus your proceeds), and the depreciation of whatever you bought. Together they're the true cost of having sold.
The interest on a loan for the same cash amount, from your sale date to today at 10% APR, plus any collateral top-ups during crashes. The calculator simulates this day by day against historical prices and compares it to what selling cost.
Yes — it looks up the actual BTC price on your sale date and every day since, so the regret figure reflects what really happened, not an assumption.
Yes. The tool generates a shareable Regret Report card and a link, so you can post your number or send it to someone weighing a sale.