Why size from volatility
A fixed 2% stop is too tight on a wild small-cap and too loose on a slow blue-chip. Volatility-based sizing fixes that: you set the stop a multiple of the coin's recent range (ATR — average true range) below entry, so the stop sits beyond normal noise. Then you size down so that distance still only costs your chosen risk %. The formula: stop distance = volatility% × multiple, then units = (account × risk%) ÷ (entry × stop distance). Calm market → tight stop → bigger size. Wild market → wide stop → smaller size. Your dollar risk stays constant either way.
How to use this calculator
Enter your account size and the % you're willing to lose on the trade (1% is a survivor's default). Put in your entry price, then the coin's recent volatility as a % of price — a quick proxy is its average daily move, or read ATR(14) off your chart and divide by price. Pick a stop multiple: 1.5× ATR is a common balance, 1× is tight, 2–3× gives the trade room to breathe. The calculator returns the exact stop price and the position size that caps your loss.
Common mistakes
• Stop too tight for the coin. A 1% stop on a token that swings 8% a day gets knocked out by noise, not by being wrong. • Forgetting leverage and liquidation. A wide volatility stop can still imply high notional — check it against the liquidation calculator so your stop sits well before liquidation. • Same size in calm and chaos. The whole point is to shrink size when volatility spikes; don't override it. • Confusing risk % with position %. Risking 1% of the account is not the same as a 1% position.
Pair this with the classic position size calculator when you already know your exact stop, and the PnL calculator to confirm the reward justifies the risk. New to sizing? Read Position size decides if you survive.
FAQ
What is ATR and where do I find it?
ATR (Average True Range) measures a coin's typical price movement over a period, usually 14 candles. Most charting tools (TradingView, exchange charts) have it as an indicator. Divide ATR by the current price to express it as the % this calculator wants. No chart handy? Use the coin's average daily % move as a rough stand-in.
What stop multiple should I use?
1.5× ATR is a sensible default — wide enough to survive normal noise, tight enough to keep size meaningful. Use 1× for tight scalps, 2–3× for swing trades that need room. The higher the multiple, the wider the stop and the smaller your position for the same dollar risk.
Does a wider stop mean more risk?
No — that's the key insight. A wider stop means a smaller position, so the dollar loss if the stop hits stays the same. You're trading position size for stop room. What changes is win-rate behaviour: wider stops get hit less often by noise but cost more per losing trade.
Is this only for crypto?
No. Volatility-based (ATR) sizing is standard across futures, FX and stocks. It's especially useful in crypto because volatility varies so much between a major like BTC and a thin small-cap — a single fixed stop % can't fit both.