Profit factor explained
Profit factor is gross profit divided by gross loss. If your winning trades made $9,000 in total and your losing trades lost $6,000, the profit factor is 1.5 — you made $1.50 for every dollar you lost. It is one of the fastest honest health checks for any trading system, and far harder to fool yourself with than win rate.
The formula
profit factorprofit_factor = gross_profit ÷ gross_loss
# Example
gross_profit = $9,000 gross_loss = $6,000
profit_factor = 9000 ÷ 6000 = 1.5
Anything above 1.0 is net profitable; below 1.0 bleeds money. Because it divides total dollars won by total dollars lost, it bakes in both how often you win and how big those wins are — the gap that win rate alone leaves wide open.
How to read it
| Profit factor | Interpretation |
|---|---|
| < 1.0 | Losing system — stop |
| 1.0 – 1.3 | Marginal, fragile to costs |
| 1.3 – 1.6 | Solid real-world system |
| 1.6 – 2.0 | Strong |
| > 2.0 | Excellent — but scrutinise for over-fitting |
If one outlier trade produced most of the gross profit, removing it can collapse a 2.5 down to 1.1. Always check the trade count and the largest winner's share before celebrating. A robust profit factor holds up out-of-sample.
Profit factor vs the other metrics
- Profit factor — dollars won per dollar lost. A blunt, honest health check.
- Expectancy — average $ per trade; pairs naturally with trade count.
- Sharpe ratio — return per unit of volatility; adds the consistency dimension.
- Max drawdown — the worst pain; survivability, which profit factor ignores.
No single number is enough. A reliable read combines profit factor with drawdown, expectancy and an out-of-sample test, as the QuantStart and CFA risk literature both stress.
Frequently asked questions
What is profit factor?
Profit factor is gross profit divided by gross loss — the total dollars won across all winning trades divided by the total dollars lost across all losing trades. A profit factor of 1.5 means you made $1.50 for every $1.00 you lost. Above 1.0 is profitable; below 1.0 loses money.
What is a good profit factor?
As a rough guide, under 1.0 loses money, 1.0–1.3 is marginal and fragile, 1.3–1.6 is solid for a real system after costs, and above 2.0 is excellent but rare and worth scrutinising for over-fitting. Always check that the figure survives fees, slippage and out-of-sample data.
How is profit factor different from win rate?
Win rate only counts how often you win; profit factor weighs how much. A system can win 40% of trades and still have a profit factor of 1.8 if the winners are large. Profit factor captures the dollar magnitude that win rate ignores, which is why it is a more honest health check.
Can profit factor be gamed?
Yes. A handful of huge outlier wins can inflate it while masking a fragile system, and tiny samples produce meaningless numbers. Look at the trade count, the largest single winner's share of total profit, and the figure on out-of-sample data before trusting a high profit factor.