Breakeven Win Rate Calculator

Break-even win rate is the minimum percentage of trades that must be profitable for a trading system to avoid losing money over time. It is one of the most important metrics in trading strategy evaluation and position sizing.

Core formula: Break-Even Win Rate = Loss Size / (Win Size + Loss Size)

Or using the risk-reward ratio (R:R): Break-Even Win Rate = 1 / (1 + Risk:Reward Ratio)

Where:

• Win Size = average profit per winning trade (in dollars or R multiples)
• Loss Size = average loss per losing trade (typically fixed as 1R)
• Risk:Reward Ratio = Win Size / Loss Size

Break-even win rates by R:R ratio:

Including transaction costs (commissions + spread): Adjusted Break-Even = (Loss + Cost) / (Win − Cost + Loss)

Expected Value (EV) per trade: EV = (Win Rate × Avg Win) − (Loss Rate × Avg Loss) A positive EV means the system is profitable long-term. A zero EV = break-even.

Worked example: A forex trader targets 1.5× risk per trade ($150 win, $100 loss). Commission: $5 round trip. Break-even = (100 + 5) / (150 − 5 + 100 + 5) = 105 / 250 = 42.0% win rate required

At a 50% actual win rate: EV per trade = (0.50 × $145) − (0.50 × $105) = $72.50 − $52.50 = +$20.00 per trade Over 100 trades: +$2,000 expected profit

Why this matters: Many traders obsess over win rate while ignoring R:R. A 35% win rate with 1:3 R:R (break-even = 25%) is far more profitable than a 65% win rate with 1:1 R:R (break-even = 50%). Track both metrics together.

Ruin probability: Even positive-EV systems go bankrupt if position sizing is too large. Risk no more than 1–2% of account per trade to survive the inevitable losing streaks.