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.