Free ATR Stop-Loss Calculator: Calculator & Guide

What the ATR Stop-Loss Calculator does

The ATR Stop-Loss Calculator takes a small set of inputs and returns a single, well-defined result. It is intentionally narrow — broad calculators tend to hide the assumptions. By keeping the surface small, you can see exactly which input drives each part of the answer.

For Volatility-Adjusted Stops, the ATR Stop-Loss Calculator is calibrated to the same defaults the TradingLens team uses when planning trades. Adjust the inputs to match your account, your instrument, and your risk tolerance.

How to use the ATR Stop-Loss Calculator

1. Enter your entry

Type the price at which you intend to enter the trade. If you have not chosen an entry yet, mark the level you are watching on the chart and use that.

2. Enter your stop

The stop is the price at which the trade idea is invalidated. Be honest about this — the ATR Stop-Loss Calculator will not save you from a poorly chosen stop.

3. Read the result

The result is the position size, the dollar risk, and the risk-percentage of your account. If any of those values look wrong, the inputs are wrong. Adjust them and re-run.

When to use the ATR Stop-Loss Calculator

Use the ATR Stop-Loss Calculator every time you are about to enter a trade, even if you have used it a hundred times before. The discipline of running the numbers before the click is what separates traders who survive from traders who do not.

Do not use the ATR Stop-Loss Calculator to justify a position you have already decided to take. If the answer disagrees with the trade you wanted, the trade is the wrong size — or the trade is wrong.

The ATR Stop-Loss Calculator is also useful before the entry, when you are still deciding whether a setup is worth taking. Plug in the planned entry and stop, and the result will tell you whether the risk is appropriate for the size of the move you are targeting.

Common mistakes with the ATR Stop-Loss Calculator

The most common mistake with the ATR Stop-Loss Calculator is rounding the stop to a "nicer" number. Every fraction of a percent in the stop changes the result, and rounding introduces silent risk. Use the actual stop from your chart.

The second most common mistake is forgetting to update the account size. The ATR Stop-Loss Calculator measures risk as a percentage of the current account, not the account you opened with. If the percentage is creeping up, the position is too large.

The third is treating the result as a recommendation. The ATR Stop-Loss Calculator is a calculator. The decision is yours.