What Is Position Sizing? The 1% Rule Explained

You cannot control where the market goes. You cannot control whether this trade wins. But you can control, with complete precision, how much you lose when you are wrong. That control is position sizing: deciding how many lots, shares, or coins to trade so that a stopped-out trade costs a fixed, pre-decided amount of money.

Most beginners do the opposite. They decide how much money they want to make, pick a round position size — one lot, a hundred shares, half a coin — and then attach a stop loss somewhere. The result is that every trade carries a different, accidental amount of risk, and no risk model survives that.

Every strategy, without exception, produces losing streaks. A solid strategy with a 55% win rate will hit five consecutive losses roughly once every hundred trades. The question is never whether the streak comes, but whether your account survives it.

Run the arithmetic. Ten consecutive losses at 1% risk per trade leave you with about 90.4% of your starting capital — painful, fully recoverable. The same ten losses at 10% risk per trade leave 34.9%. To recover from that you need to nearly triple what is left. Same strategy, same entries, same exits — the only difference is the size of each trade. Position sizing is the difference between a drawdown and a funeral.

Position sizing is one division: position size = (account balance × risk %) ÷ stop distance. The stop distance comes from the chart — a support level, a volatility measure, a structure break. The risk percentage comes from your risk plan. The formula connects the two.

• Account balance: your total trading capital.
• Risk %: the fraction you accept losing if stopped — the 1% rule is the standard starting point.
• Stop distance: entry price minus stop loss price, in price units or pips.

You have a $10,000 account and risk 1% — $100 per trade. On EUR/USD you plan to enter at 1.1000 with a stop at 1.0950, a 50-pip distance. One pip on a standard lot is worth $10, so one standard lot risks 50 × $10 = $500 on this trade. Your size is $100 ÷ $500 = 0.20 standard lots — two mini lots, or twenty micro lots.

Notice what happened: the chart chose the stop, the rule chose the risk, and the formula chose the size. Nothing was guessed. Our position size calculator does this in one step, including the currency conversion when your account currency is not the pair's quote currency.

Same account, same rule: $10,000, 1% risk, $100 per trade. A stock trades at $50, and your stop sits at $47 — a $3 distance. Shares = $100 ÷ $3 ≈ 33 shares. The position is worth $1,650 — only 16.5% of your account — yet the risk is exactly 1%. Position value and amount at risk are different numbers; confusing them is one of the most common sizing errors.

The 1% rule says: never risk more than 1% of account equity on a single trade. It is not magic; it is a survivability guarantee. At 1% risk, even twenty consecutive losses — a streak that would end most strategies psychologically before it ends them mathematically — leaves about 82% of the account intact.

When does 0.5% make sense? When trading volatile assets like altcoins or gold, when running a new untested strategy, or when trading correlated positions that can lose together. When does 2% make sense? Rarely — typically only for high-win-rate strategies with a long verified track record. Above 2%, the recovery math turns hostile fast: a 50% drawdown requires a 100% gain just to break even.

Every blown account traces back to a short list of repeatable errors. Avoid these and you are ahead of most traders.

• Sizing by conviction: 'this one is special, I'll go bigger.' Confidence is not an input to the formula.
• Choosing lot size first, stop second: the stop must come from the chart; the size follows from the stop.
• Widening a stop after entry without reducing size: that silently doubles your risk.
• Ignoring currency conversion: a USD/JPY pip is not worth the same as an EUR/USD pip in a EUR account.
• Averaging down into losers: adding to a losing position at the original size multiplies risk beyond the plan.

Position sizing is a habit, not a theory. Before your next trade, run the numbers: our position size calculator covers forex, crypto, and stocks; the lot size calculator translates the result into standard, mini, and micro lots; the pip value calculator shows what each pip is worth in your currency; and the risk-reward calculator checks whether the trade is worth taking at all. Ten seconds of math, before every trade, forever.