Free tool. No account needed.

Risk Calculator

How much of your account should one trade risk? Put in how often your strategy wins and how big its wins are next to its losses, and see the answer, along with the half and quarter amounts most traders actually use.

Use at least 30 trades from your journal or a backtest. A rate you hope for is not a rate you have.

How much to risk per trade

Full
-
Half
-
Quarter
-
Enter your numbers above.
Payoff ratio-
Edge per 1 risked-

Before you use the number

  • The maths assumes your win rate and payoff are known and stay the same. Real ones drift, so a figure that is slightly too high costs far more than one that is slightly too low. That is why half or quarter is the usual choice.
  • It sizes one trade at a time. Several open positions that move together are, for this purpose, one larger trade.
  • A firm's daily loss limit or drawdown floor can make even the half amount too large. The calculator knows nothing about those rules.

Based on the Kelly formula, a standard rule for sizing a position when you know your edge. Educational only, not financial advice. The result is arithmetic on the numbers you enter, not a recommendation to trade.

Turn it into a position size you can defend

The member Risk Management Tools take it from here: a dollar size for your account, a margin for being wrong about your own win rate, a check against prop-firm drawdown rules, and a stress test of how the account holds up through a losing run.