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Trading Edge Calculator
See what costs and losing streaks could mean for your trades. Start with your trade log, or try the example below.
Your Trade Results
Use trades with the same rules. Enter wins and losses before costs. The starting numbers are just an example.
What does R mean?
R means the amount you planned to risk. Here, 1R = $100 and 2R = $200. $100 is an example, not a suggested amount.
60% means 60 wins out of 100 trades.
$100.00 profit before costs in our $100 risk example.
$100.00 loss before costs. Use what you actually lost, even if it was more than planned.
$1.00 per trade. Include fees to enter and exit, plus worse fills. Count each cost only once.
Count only trades that follow your rules.
What your numbers show
Too long to check at this pace.
The expected gain is hard to tell from luck. Markets may change before you have enough trades to check it.
This doesn't prove your setup works. Don't chase a trade count.
Per trade in our $100 risk example. An average, not a promise.
38,401 trades at 5 a week. A rough estimate, not proof.
How the math works
The average result is win rate times average win, minus loss rate times average loss, minus costs. For example, 60% winners earning $100 and 40% losers losing $100 leave $20 per trade before costs. Subtract $1 per trade and the average is $19. Those are hypothetical numbers.
The sample estimate uses a normal approximation. It finds the trade count where 1.96 times the model's standard deviation, divided by the square root of the trade count, equals the estimated average result. This assumes independent trades with unchanged win rates and fixed win, loss and cost amounts. Real trades don't fit that neatly. It isn't a measured confidence interval or a guarantee of detecting an edge. Even with unchanged conditions, reaching this count does not reliably confirm a gain. We show a time estimate only when that rounded trade count includes at least ten expected wins and ten expected losses. Outside those limits, this shortcut cannot give a useful estimate. We flag waits of ten years or more as long waits, not as a statistical verdict.
Fees cover entry and exit. Slippage is the gap between the price you expected and the price you actually got. Don't add it again if your recorded wins and losses already include it. Stops don't guarantee a fill price.
Read NIST's explanation of confidence intervals. Read Penn State's normal approximation conditions.
Theoretical half-Kelly estimate: 0.5%. Kelly is a formula for the fraction of a bankroll put at risk in a fixed win/loss model. Half-Kelly is half that fraction. This version adjusts the payouts for costs. It assumes your inputs are correct and doesn't model your account's drawdown limits or the range of possible losses. This number is not a recommended position size.
How many losses in a row should I expect?
Move the sliders. Your losing-streak estimate updates automatically.
60% means 60 wins out of 100 trades. You can also type a number.
How many trades do you want to look at? Choose 1 to 5,000.
Your answer
6 losses in a row
That is a typical longest losing streak over 100 trades at a 51% win rate.
Allow for a longer streak, too. 9 losses in a row is still realistic in this model.
These are estimates, not a limit. Longer streaks can happen.
Real losses can bunch together. Plan for worse streaks, too.
Check the chance of a specific losing streak
Choose 1 to 20 losses. Each slider step adds one loss.
With a 51% win rate, you have a 78.1% chance of losing 5 or more trades in a row at least once during 100 trades.
These estimates assume each trade has the same chance of winning and trades don't affect each other. They don't calculate your chance of running out of trading money.
The typical streak is the middle of the model's range. In at least half of groups of 100 trades, the longest losing streak is 6 or fewer.
For the longer streak, at least 95 out of 100 groups have a longest streak of 9 or fewer in this model. Longer streaks are still possible. This is not a maximum.
In our $100 planned risk example, 5 losses matching your average loss, plus the costs you entered, would cost $505.00. Actual losses can be larger. This is a dollar example, not an estimate of the biggest drop in your account balance.
Loss size and costs change how much money you lose, not these streak odds. A trade counted as a win before costs can still lose money after costs.
Test the setup before you trade it live.
Keep your rules the same. Track every trade that follows them. Don't take extra trades just to reach a number.
Want to work through an example?
Follow a simple example, then try your own numbers. No email needed.
Read the Worked ExampleEducational tool only. Nothing on this page is investment advice or a guarantee of results. Calculations are simplified statistical models; live trading involves risks these models do not capture. Trading involves substantial risk of loss. Full risk disclosure.