What Is the 3-5-7 Rule in Trading?

The 3-5-7 rule is a simple risk framework: risk no more than 3% of your account on any one trade, keep no more than 5% at risk across all open trades together, and make sure your winning trades are larger than your losing ones, with 7% often given as the target for a winner relative to the account. It is a rule of thumb, not an official standard, and different educators describe the third number slightly differently. Its value is that it gives you hard limits on how much a bad day can cost.

The three numbers, one by one

3%: the cap on a single trade

The first number limits the damage from any one idea. On a $5,000 account, 3% is $150. If the trade hits its stop-loss, you lose $150 and nothing more. The stop-loss distance then decides the position size, not the other way round.

For example, a EUR/USD trade with a 50-pip stop on a $5,000 account: $150 ÷ 50 pips = $3 per pip, which is 0.3 standard lots, because one standard lot is worth about $10 per pip on EUR/USD. A wider 100-pip stop would halve the size to 0.15 lots. Our position size calculator does this for any pair.

5%: the cap on everything open at once

The second number stops a common trap: several trades that look separate but lose together. If you are long EUR/USD, long GBP/USD and short USD/CHF, all three trades are bets against the US dollar. One strong dollar report can stop out all three at once.

The 5% limit adds up the risk on every open position. With a 3% trade already open, you have 2% left for anything else. Two full 3% trades would put 6% at risk and break the rule.

7%: making winners pay for losers

The third number is the one that varies most between versions. The common reading is that a winning trade should aim to make around 7% of the account, more than twice the 3% you risk. Others express it as a minimum reward-to-risk ratio of roughly 2:1. Either way the idea is the same: if your winners are bigger than your losers, you do not need to win most of the time.

With a 3% risk and a 7% target, the reward-to-risk ratio is about 2.3 to 1. At that ratio a strategy breaks even, before costs, with a win rate of about 30%: 0.3 × 7 = 2.1, and 0.7 × 3 = 2.1. Every percentage point of win rate above that is profit.

Those totals are simple sums to show the logic. Real results also depend on spreads, commissions, slippage and the order in which wins and losses arrive.

Putting it together: a worked example

Take a $5,000 account. The rule gives three hard numbers: $150 maximum risk on a trade, $250 maximum risk across open trades, and a target of about $350 on a winning trade.

1. You buy EUR/USD with a 50-pip stop: 0.3 lots risks $150. Open risk is now 3%.
2. A second setup appears on gold. You may risk only another $100, the 2% left under the 5% cap, so you size it smaller.
3. A third setup appears. You have no risk budget left, so you skip it, even though it looks good.
4. EUR/USD reaches its target for about $350. Its risk is now gone, so the budget frees up again.

The rule on a small account

The 3-5-7 rule gets harder to apply as accounts get smaller, because lot sizes cannot be divided forever. On a $500 account, 3% is $15. With a 20-pip stop on EUR/USD, that allows $0.75 per pip, which is 0.075 lots. Most brokers let you trade in steps of 0.01 lots, so you would round down to 0.07 lots and risk about $14.

Now try a 40-pip stop on the same account: $15 ÷ 40 = $0.375 per pip, or 0.0375 lots, which rounds down to 0.03 lots. The rule still works, but only because micro lots exist. On a cent account the steps are even finer, which is one reason small-account traders often choose one; our comparison of cent and standard accounts explains the trade-off.

Two practical rules follow. First, always round the lot size down, never up, so the real risk stays at or below your limit. Second, if a sensible stop-loss gives a lot size below 0.01, the trade is too big for the account and should be skipped, not squeezed in with a tighter stop than the chart allows.

Strengths and weaknesses

• Strength: it is easy to remember and turns vague caution into hard numbers.
• Strength: the 5% cap catches hidden concentration that per-trade rules miss.
• Weakness: 3% per trade is aggressive for beginners and small accounts.
• Weakness: a fixed 7% target can be unrealistic on quiet days; the ratio matters more than the exact number.

Used sensibly, the 3-5-7 rule is a good starting structure. Adjust the first two numbers to your experience, for example 1-3-7 or 2-4-6, and keep the principle: limit each trade, limit the total, and let winners be bigger than losers. Compare it with the 2% rule on a $1,000 account to see how much smaller accounts change the picture.

Frequently asked

Related reading

• The 2% rule on a $1,000 account
• Position size calculator
• Forex risk management