Every consistently profitable trader I know follows one unbreakable rule: they never risk more than 1% of their total account balance on a single trade. This single rule is the reason some traders last decades, while others blow up in months.
What is the 1% Rule?
The 1% rule means that if your trade hits your stop loss, the maximum you will lose is 1% of your account. On a $10,000 account, that means your maximum loss per trade is $100. Not $500, not $200 — $100.
This sounds simple, but most losing traders violate this every single day because they don't know how to calculate their position size correctly.
How to Calculate Your Position Size
Here is the exact formula I use on every single trade:
Example: $100 risk ÷ (20 pips × $10/pip) = 0.50 lots
On a standard lot account with a USD quote currency, each pip is worth approximately $10 per standard lot. So if your stop loss is 20 pips and you want to risk $100:
$100 ÷ (20 × $10) = 0.50 lots
Use a position size calculator if the math feels overwhelming. There are dozens of free tools online. The calculation itself takes 10 seconds — there is no excuse to skip it.
Why 1% and Not More?
The math of survival in trading is brutal. If you risk 10% per trade and hit 5 consecutive losing trades (which any strategy can produce), you have lost 41% of your account. At 1% risk, 5 consecutive losses only costs you 4.9% of your account.
- At 1% risk: 10 consecutive losses = 9.5% drawdown. Recoverable.
- At 5% risk: 10 consecutive losses = 40% drawdown. Devastating.
- At 10% risk: 10 consecutive losses = 65% drawdown. Account destroying.
The Daily Loss Limit Rule
On top of the 1% per-trade rule, I have a hard daily loss limit of 3%. If I am down 3% on the day, I close my platform and do not trade again until the next session. This prevents emotional spiraling from destroying a week of profits in a single bad day.
Risk-to-Reward: Why It Matters as Much as Win Rate
A trader with a 40% win rate and a 1:3 Risk-to-Reward ratio is MORE profitable than a trader with a 60% win rate and a 1:1 ratio. Always aim for a minimum of 1:2 Risk-to-Reward on every trade you take.