Stop-Loss Calculator
A stop-loss is only meaningful once you know what it costs if it's hit. Enter your entry, your stop and how much you're buying, and this shows the dollars at risk, how far the stop sits from entry, and — the number that matters most — the share of your whole account on the line.
- • Per share = entry − stop · Total at risk = per-share × position size.
- • Move to stop = (entry − stop) ÷ entry · % of account = total at risk ÷ account size.
Worked example: enter at $100, stop at $92, 100 shares, $10,000 account → $800 at risk, an 8% move to the stop, 8% of the account — well above the 1–2% many traders cap per trade.
This assumes a long trade filled at your entry and a stop that fills exactly at your stop price — real fills gap and slip, especially in fast markets, so treat the risk figure as a best case. To size the trade the other way round — from the risk you'll accept — use the position-size calculator. Educational tool, not advice.
A calculator shows what a rule should do on paper. Whether a strategy actually beats simply buying and holding — costs on, losses shown, no hindsight — is a different question, and the only one that pays. Most rules don't beat holding; the backtest is how you find the rare few that do — so when you build one that survives, you'll know it isn't a fake edge, then prove it forward before you risk real money. It won't tell you you'll win — nothing honest can.