How to Calculate Risk-Reward Ratio Before Every Trade

Risk-reward ratio is calculated as (Entry Price - Stop Loss Price) : (Target Price - Entry Price), expressed as a ratio like 1:2 or 1:3. This post walks through the exact calculation step-by-step, with numbers, so you can run it as a checklist before every trade rather than eyeballing it. For a deeper look at why the ratio matters strategically and how it interacts with win rate, see Risk-Reward Ratio Explained.

The Formula, Broken Into Steps

1. Identify your entry price — the price you plan to buy (or short) at.
2. Identify your stop-loss price — the price at which you'll exit if the trade goes against you. This should be set at a technically meaningful level (below support, above resistance), not an arbitrary percentage.
3. Identify your target price — where you realistically expect to take profit, based on the next resistance/support level, a measured move, or a prior swing high/low.
4. Calculate risk = Entry - Stop Loss (for a long position).
5. Calculate reward = Target - Entry (for a long position).
6. Divide reward by risk to get your ratio.

Worked Example: A Long Stock Trade

Suppose you're considering a long entry on a stock at $50, with a stop-loss placed below recent support at $47, and a target at the next resistance level of $59.

Component	Value
Entry	$50.00
Stop-loss	$47.00
Target	$59.00
Risk per share	$50 - $47 = $3.00
Reward per share	$59 - $50 = $9.00
Risk-reward ratio	$9 ÷ $3 = 3:1

A 3:1 ratio means you're risking $1 to potentially make $3. This is generally considered an attractive setup, since it can be profitable even with a win rate well below 50%.

Worked Example: A Short Trade

For a short position, the risk and reward sides invert:

• Risk = Stop Loss - Entry
• Reward = Entry - Target

Example: short entry at $80, stop-loss at $84, target at $68.

• Risk = $84 - $80 = $4
• Reward = $80 - $68 = $12
• Ratio = $12 ÷ $4 = 3:1

Connecting Risk-Reward to Win Rate: The Breakeven Formula

A risk-reward ratio only tells half the story — it needs to be paired with your realistic win rate to know if a strategy is profitable. The breakeven win rate for a given ratio is:

Breakeven win rate = Risk ÷ (Risk + Reward)

Risk-Reward Ratio	Breakeven Win Rate Needed
1:1	50%
1:2	33.3%
1:3	25%
1:4	20%

At a 3:1 ratio, you only need to win 25% of your trades to break even — anything above that is net profitable before accounting for fees and slippage. This is why traders with modest win rates (40-50%) can still be consistently profitable if they enforce a minimum risk-reward threshold on every entry.

Turning This Into a Pre-Trade Checklist

Run this before entering any position:

1. Mark your stop-loss level first, based on structure (not a fixed dollar amount you're comfortable losing).
2. Mark your realistic target, based on the next real resistance/support level — not wishful thinking.
3. Calculate the ratio using the formula above.
4. Compare the ratio against your minimum threshold (many traders use 2:1 or higher as a hard floor).
5. If the ratio doesn't clear your threshold, either the entry is wrong, the stop is too wide, or the setup isn't there — skip the trade rather than lowering your standard after the fact.
6. Only after confirming the ratio, size the position using your risk-per-trade rule (see Position Sizing Guide) — risk-reward tells you if the trade is worth taking; position sizing tells you how big to make it.

Common Calculation Mistakes

• Moving the stop after entry to "make the ratio work" — the ratio must be calculated and locked in before you enter, using a stop placed on structure, not moved after the fact to justify a trade you already want to take.
• Setting unrealistic targets — a target beyond any real resistance level inflates your reward-side number and produces a ratio that looks better than the trade actually is.
• Ignoring fees and slippage — on lower-priced or less liquid instruments, transaction costs can meaningfully erode a marginal ratio like 1.2:1.

Summary

Risk-reward ratio is a simple division — reward divided by risk — but its value comes from calculating it consistently, before entry, using a stop and target both grounded in actual price structure. Pair the ratio with the breakeven win-rate formula to judge whether a setup is statistically worth taking, and only then move to sizing the position.

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Related reading:

• Risk-Reward Ratio Explained: How to Structure Trades for Long-Term Profitability
• Position Sizing: How to Calculate How Much to Risk Per Trade
• ATR (Average True Range) for Stop-Loss Placement
• Kelly Criterion for Position Sizing Explained