Stop Loss Calculator — Find Your Exit Before You Enter
A stop loss calculator works backward from your max acceptable loss to the exact price you should exit at if a trade goes wrong. Enter your account size, the percent you're willing to risk, your entry price, and the number of shares you plan to buy — we'll calculate the stop-loss price that limits your loss to your target risk amount.
Results
Stop-loss price
$95.00
Exit here if the trade goes against you. For longs, set this on entry — don't wing it later.
Stop distance from entry
5.00%
How far the price needs to fall to hit your stop.
Risk per share
$5.00
Per-share loss if your stop triggers.
Total dollar risk
$250.00
Total loss if the trade fails — should match your account-risk target.
Position value
$5,000.00
Total capital deployed in this trade.
Results update live as you change inputs. This calculator runs entirely in your browser — your numbers are never sent to a server.
Worked example
You have a $25,000 account and you'll risk 1% ($250) on this trade. You're buying 50 shares at $100 (a $5,000 position). Your per-share risk = $250 ÷ 50 shares = $5/share. Set your stop-loss at $100 − $5 = $95, which is a 5% drop from entry. If price hits $95, you exit and lose exactly $250 — your pre-defined max risk.
Frequently asked questions
What is a stop loss calculator?
A stop loss calculator works backward from your maximum acceptable loss to the exact price you should exit at. You input your account size, risk percentage, entry price, and share count — it returns the stop-loss price that caps your loss at the target amount. It removes guesswork from setting stops.
What's a good stop loss percentage?
Most swing traders set stops 3-8% below entry; day traders 0.5-2%. The right number depends on the stock's average true range (ATR) and your strategy's win rate. A stop too tight gets shaken out by normal noise; a stop too wide kills your risk/reward math. Use ATR × 1.5-2 as a starting point.
Should I use a hard stop or a mental stop?
Use a hard stop (a real order placed with your broker). Mental stops fail in fast markets, after-hours news, and during connectivity outages — exactly when you need them most. The only exception is highly illiquid stocks where stop orders can be picked off by HFTs, in which case use a stop-limit.
Does the calculator account for slippage and commissions?
No — the result is the theoretical exit price. On commission-free brokers (Robinhood, Fidelity, Schwab) with liquid US equities, slippage on a stop order is typically $0.01-0.05/share. Subtract that from your stop price if you want a more conservative real-world number, or just risk slightly less than your target to absorb it.
What's the difference between a stop loss and a trailing stop?
A fixed stop loss stays at the same price; a trailing stop moves up with the stock (locking in gains as it rises but never moving down). Use a fixed stop on entry, then convert to a trailing stop once the trade is 1R+ in profit. This calculator computes the initial fixed stop.
How is this different from the position size calculator?
Position size calculator: you know your stop, it tells you how many shares to buy. Stop loss calculator: you know how many shares you're buying, it tells you where to set the stop. They're inverses of the same formula — use whichever matches your decision order.