In a standard fixed-payout binary option you know the risk and the reward before you click: the risk is your stake, and the reward is the stake multiplied by the payout percentage. That makes the risk to reward ratio simple to calculate and easy to ignore. This guide shows the maths, the break-even win rate at common payouts, and how to judge a strategy using expected value instead of win rate alone.
TL;DR -- Key Takeaways
- Risk to reward is the payout compared with the stake. A payout of 85% means a risk of 1 for a reward of 0.85.
- Break-even win rate = 1 divided by (1 + payout). At an 85% payout it is about 54.05%.
- Expected value per trade = win rate x (1 + payout) - 1, expressed as a fraction of the stake.
- A lower payout raises the win rate you need. Payout is part of your strategy, not a detail.
- Win rate measured over a small sample is unreliable. Use a large sample before relying on it.
1. The Basic Ratio
If you stake 10 at an 85% payout:
- A win returns a profit of 8.50.
- A loss costs 10.
The reward is smaller than the risk, so you must win more often than you lose just to stand still. That is the opposite of the ratios many traders know from other markets, where the reward target can be larger than the risk. In a fixed-payout binary option the ratio is set by the payout and cannot be adjusted trade by trade.
2. The Break-Even Win Rate
The break-even win rate is the share of trades you need to win so that wins and losses cancel out. The formula is:
Break-even win rate = 1 / (1 + payout)
| Payout | Break-even win rate |
|---|---|
| 90% | 52.63% |
| 85% | 54.05% |
| 80% | 55.56% |
| 75% | 57.14% |
| 70% | 58.82% |
| 65% | 60.61% |
| 60% | 62.50% |
Moving from an 85% payout to a 70% payout raises the required win rate by about 4.8 percentage points. A strategy that is profitable at 85% can lose at 70%, with no change in how well you read the chart.
3. Expected Value Per Trade
Expected value (EV) combines win rate and payout into one number:
EV (as a fraction of stake) = win rate x (1 + payout) - 1
Worked examples at an 85% payout:
- Win rate 54%: 0.54 x 1.85 - 1 = -0.001, almost zero but slightly negative.
- Win rate 56%: 0.56 x 1.85 - 1 = +0.036, or about 3.6% of the stake per trade on average.
- Win rate 50%: 0.50 x 1.85 - 1 = -0.075, or about 7.5% of the stake lost per trade on average.
An EV of +3.6% does not mean you gain on every trade. It means the average outcome over a large number of trades. With a small sample, luck can easily outweigh edge.
4. Why a High Win Rate Can Still Lose
Because the reward is smaller than the risk, one loss needs more than one win to recover. At an 85% payout you need roughly 1.18 wins to recover one loss. A series of eight wins and two losses at an 85% payout returns 8 x 0.85 - 2 = 4.8 units of stake, which is a profit. A series of six wins and four losses returns 6 x 0.85 - 4 = 1.1, a thin profit. Seven wins and six losses (a 54% win rate) returns 7 x 0.85 - 6 = -0.05, a small loss.
The takeaway is that win rate has no meaning without the payout beside it. A trader quoting a win rate without a payout is quoting half the number.
5. How to Use the Ratio in Practice
- Know your payout before you enter. Payouts change by asset, time of day and expiry. Check it on the ticket.
- Know the break-even rate for that payout. Keep the table above in your journal.
- Track results by payout band. A mixed log hides the fact that lower-payout trades need a higher win rate.
- Set a minimum payout. Many traders decide not to trade assets below a chosen payout. Choose your own number from your tested results.
- Do not raise stake to recover losses. Larger stakes after losses increase risk without changing the break-even rate. See martingale and money management strategies.
6. Higher Payout Products
Products such as touch or ladder options can offer a higher payout but a lower chance of winning. The ratio looks better, but the break-even win rate falls only because the event is harder to achieve. The EV formula still decides whether it works. See touch, ladder and straddle option strategies.
Frequently Asked Questions
What risk to reward ratio is good for binary options?
There is no single good ratio, because the ratio is set by the payout. What matters is whether your tested win rate is above the break-even rate for that payout.
How many trades do I need to trust a win rate?
Far more than most traders expect. Short runs are dominated by luck. Use a large sample from a written strategy, ideally tested on historical charts and then on a demo account.
Does a higher payout always mean a better trade?
No. A higher payout lowers the break-even rate, but only a tested win rate tells you whether the trade has positive expected value.
Do brokers' payouts change?
Payouts can differ by asset and time and can change, so read the payout on the ticket for each trade.
Related Reading
- Binary Options Win Rate Realities -- the mathematics of win rate and payouts in more depth
- How to Build and Backtest a Binary Options Strategy -- measuring win rate on a proper sample
- Money Management Strategies -- why stake changes do not change the maths
- Risk Management Hub -- position sizing and daily limits
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