A risk to reward ratio is two distances measured off the same chart: how far from your entry to your stop, and how far from your entry to your target. Divide the second by the first and you have the number. That’s the whole definition. Where people get it wrong isn’t the division. It’s where the two distances come from in the first place.
Most explanations of risk to reward stop at the formula and move on, as if the hard part were the arithmetic. It isn’t. A fourth grader can divide one number by another. The hard part is that both numbers have to come from the chart, not from a target ratio you liked the sound of before you’d looked at anything.
The calculation, in full
Risk is entry minus stop. Reward is target minus entry. The ratio is reward divided by risk, usually written as reward-to-risk with the reward number first — a 3:1 trade risks one dollar to make three. Some people write it risk-first, 1:3, meaning the same thing. Either way, the risk to reward ratio only means something once you know what stop and what target you’re actually using, and both of those have to be real prices, not round numbers picked for how clean the ratio looks.
Here’s the calculation on an actual setup. A stock is holding support at $41.20, tested twice in the prior ten sessions, both times with a wick that stayed inside twenty cents of the level before closing back above it. Above the entry, there’s a resistance shelf at $44.10 that price has failed to close above three separate times over the past month. You buy the bounce at $41.50. Your stop sits at $40.85, thirty-five cents below the level — enough room to survive the noise those two prior tests already showed you, following the same level-reading approach covered in where to place a stop loss. Your target is $44.00, ten cents under that resistance shelf, because a shelf that’s turned price away three times is not a level you assume breaks on the fourth try.
Risk: $41.50 minus $40.85, or $0.65. Reward: $44.00 minus $41.50, or $2.50. Divide $2.50 by $0.65 and the risk to reward ratio comes out to roughly 3.8:1. Not because 3.8 sounds impressive. Because that’s what the actual gap between two actual levels produced once the stop and target were both placed honestly. That’s the full calculation — no formula beyond the one division, once both prices are real.
The target has to be a level, not a number you wanted
This is the part that gets skipped. The stop-placement piece I linked above covers how the stop side of the equation gets measured off a level’s own noise — that mechanics doesn’t need repeating here. But a risk to reward ratio has two sides, and the reward side gets the sloppy treatment far more often than the risk side does.
The common version of the mistake: a trader decides in advance that they only take “3:1 or better” setups, which sounds disciplined until you watch how the target actually gets chosen. They’ve got their entry, they’ve got their stop, and now they need a target that clears 3:1 — so they multiply the stop distance by three, add it to the entry, and call whatever price falls out “the target.” On the trade above, that would mean skipping the real resistance shelf at $44.10 entirely and inventing a target near $43.45 instead, purely because $0.65 times three lands there. That price has no relationship to anything on the chart. Nothing ever happened at $43.45. It’s not where sellers have shown up before. It’s a number generated by a ratio, wearing the costume of a target.
A target has to be a level for the same reason a stop has to be a level — because a level is the only thing on the chart that’s actually shown you where price has behaved differently in the past. A resistance shelf that’s rejected price three times is telling you something. A number you got from multiplying your stop distance by three is telling you nothing except that you’re good at multiplication. If the real target, the one where actual sellers have shown up before, only gets you 1.4:1, then 1.4:1 is the honest risk to reward ratio on that trade. Forcing a fake 3:1 target doesn’t make the trade better. It just makes the number on your spreadsheet look better while your actual exit sits at a price with no history behind it.
Why a lower win rate can still make money
Here’s the math that makes the risk to reward ratio worth calculating in the first place, worked out with real numbers instead of a slogan about letting winners run.
Take a trader risking $100 a trade with a 3:1 ratio, winning 40% of the time. Out of ten trades: four winners at $300 each is $1,200. Six losers at $100 each is $600. Net: plus $600 across ten trades, from a strategy that loses on six trades out of ten.
Now take a trader risking $100 a trade with a 1:1 ratio, winning 65% of the time — a win rate most people would call excellent, twenty-five points better than the first trader. Out of ten trades: 6.5 winners at $100 is $650, call it $700 rounding to seven winners and three losers to keep it in whole trades. Seven winners at $100 is $700. Three losers at $100 is $300. Net: plus $400 across ten trades.
The trader who was wrong six times out of ten made more money than the trader who was right seven times out of ten. That isn’t a trick of the numbers. It’s the entire reason the risk to reward ratio matters more than win rate on its own. A high win rate with a bad ratio can lose money the same way — drop that second trader’s ratio to 1:2, still winning 65%, and the math flips negative: seven winners at $100 is $700, three losers at $200 is $600, net plus $100 across ten trades, most of the edge gone despite being right most of the time. Push the ratio to 1:3 at that same 65% win rate and it goes fully negative: seven winners at $100 is $700, three losers at $300 is $900, net minus $200 across ten trades that were mostly winners.
Win rate tells you how often you’re right. Risk to reward ratio tells you what being right is worth against what being wrong costs. Neither number means much without the other, but a trader who only tracks win rate is watching the wrong side of the ledger. Track both, and the risk to reward ratio is usually the one that explains a losing month more honestly than the win rate does.
What this changes about picking trades
None of this means chase the highest risk to reward ratio available. A trade with a 6:1 ratio and a target that’s never been tested by price is worse than a trade with a 1.5:1 ratio and a target sitting exactly where sellers have shown up three times before. The ratio is a description of the trade you found, not a filter you apply before you’ve looked at the chart. Calculate it after the stop and target are both placed on real levels, and let the number tell you what it tells you — sometimes 3.8:1, sometimes 1.4:1, always honest about which levels actually produced it.
What it does change is the arithmetic behind every trade you take. Once the risk to reward ratio on a setup is real — both sides measured off levels that have actually held or actually failed before — you know exactly what a string of losses costs you and exactly what one clean winner buys back. That’s a different kind of confidence than a win-rate streak. It survives the losses instead of being erased by the first one.
Writing it down before the trade, not after
The risk to reward ratio only does its job if it’s calculated before entry, sitting next to the stop and the target on paper or in a notes app, not reconstructed afterward to explain a result. Calculated after the fact, the number turns into a story you tell yourself about a trade you already took. Calculated before, it’s a filter — a fast way to see that a setup with a real stop at $40.85 and a real target at $44.00 clears 3:1, or that a different setup with a cramped target barely clears 1:1 and probably isn’t worth the screen time.
That habit alone changes which trades get taken. Two setups can look equally clean on the chart — same clarity of level, same confidence in the read — and still be worth entirely different amounts once the risk to reward ratio on each is written down side by side. The one with more room between entry and the nearest real resistance wins the slot in the day. The one where the target sits close enough that a single ordinary pullback would tag it gets skipped, not because the level reading was wrong, but because the ratio said the math wasn’t there.
I mark levels for both the stop and the target before I’m ever in a trade, in Static, the free daily chart room run by Draw Lines Make Money. If seeing the risk to reward ratio worked out on real charts, before the trade happens, would help it stick, you can sit in and watch:
Join the free Static chart room →
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