Risk-Reward and Position Sizing: Managing Risk by the Numbers

What is risk-reward (R:R)?

Risk-reward is the ratio between the risk you accept and the profit you target on a single trade.

• Distance to your stop-loss = your risk (1R)
• Distance to your take-profit = your reward
• Example: a 20-tick stop and a 40-tick target → 1:2 (R:R = 2)

Expressing trades in “R” units lets you compare setups on equal footing, no matter the market or the dollar size involved.

Win rate and risk-reward go together

A high win rate alone does not make you profitable — your risk-reward has to back it up. The better your R:R, the lower the win rate you need just to break even.

Risk-reward	Break-even win rate (approx.)
1:1	Need roughly 50% or more
1:2	Break even around 34% or more
1:3	Break even around 25% or more

In other words, a strong risk-reward lets you survive even with a low win rate. Once you subtract commissions and slippage, the win rate you actually need climbs a little higher. → Understanding commission and fee structures

Position sizing: working backward to contract count

The core of controlling risk is to calculate your contract count backward from your loss limit — not from how confident you feel about the trade.

Example: with a $100 loss limit, a 20-tick stop, and a $5 tick value → 100 ÷ (20 × 5) = 1 contract. For how tick value is derived, see → Ticks and tick value.

Sizing this way means a trade with a wider stop automatically gets fewer contracts, so the dollar risk on every trade stays roughly constant regardless of where you place your stop.

Start with the per-trade loss limit

• Fix a set percentage of your account (e.g., 1–2%) as the most you will lose on any single trade.
• This limit becomes the anchor for every position size. → Leverage and risk management
• The goal is to let your account shrink slowly through a losing streak so you can stay in the game long enough for your edge to play out.

Practical tips

• Stop first, target second — decide your stop distance (1R), then set your target as a multiple of it. Never reverse the order.
• Don’t widen your stop just to inflate the target — doing so quietly increases your real risk.
• Log and review — record outcomes in R units, and the expected value of your strategy becomes visible over time. → How to keep a trading journal

Let the arithmetic pick your size

The contract-count formula above only pays off if you run it before every entry, rather than admiring it once. In Merini’s free web demo you can set the stop and the target on the order ticket, see the margin the position requires, and then check afterwards in the trade history and stats whether your realised results match the R you intended. The discipline worth rehearsing is the one this article warns about: place the stop first, and never widen it later to make the target look better → Size a trade by the numbers

Frequently asked questions

Is a higher risk-reward always better?

No. Set the target too far away and price often reverses before reaching it, which causes your win rate to collapse. A target that reflects the market’s actual volatility matters more than simply chasing a big number.

Why am I losing money even with a high win rate?

If your risk-reward is poor — small wins and large losses — even a high win rate can be wiped out by one or two oversized losses. That is exactly why win rate and risk-reward have to be evaluated together, never in isolation.

Related reading → Leverage and risk management · Ticks and tick value · How to keep a trading journal