Calculate the right position size for any trade. Enter your account size, risk %, entry, and stop loss.
Most traders spend the majority of their time refining entries and exits. Very few spend proportionate time on position sizing — despite the fact that sizing has a larger impact on long-term outcomes than almost any other single variable in trading.
The formula is simple: Position Size = Dollar Risk ÷ Risk Per Share. Dollar risk is your account size multiplied by your risk percentage. Risk per share is the distance from your entry price to your stop loss. If you risk 1% of a $10,000 account on a trade where the stop is $2 away from entry, your position size is $100 ÷ $2 = 50 shares.
The 1% rule — never risk more than 1% of your account on a single trade — is a widely used guideline for a reason. At 1% risk, you can lose 20 consecutive trades and still have 82% of your account intact. At 5% risk, the same losing streak takes you below 36% of your starting capital — a hole that is extremely difficult to recover from psychologically.
For prop firm traders, position sizing is even more critical. Most prop firms set a daily loss limit of 4–5%. If you risk 1% per trade, you need four consecutive full losses to hit your daily limit. That gives you buffer. If you risk 3% per trade, two bad trades ends your trading day — and the pressure that creates tends to make the second bad trade more likely, not less.
Most professional traders risk between 0.5% and 2% of their account per trade. The classic '1% rule' — never risk more than 1% on a single trade — is a good starting point for most traders. Prop firms typically require traders to risk even less, often 0.5% or below, due to daily loss limits.
Prop firms focus heavily on daily loss limits — typically 4% to 5% of the account. If you risk 1% per trade, you can afford 4 or 5 losing trades before hitting your daily limit. Many funded traders use 0.5% risk per trade to allow more losing trades in a day while staying within rules.
R-multiple expresses a trade's profit or loss as a multiple of the initial risk. A +2R trade means you made twice what you risked. A -1R trade means you lost exactly your planned risk amount. R-multiples allow you to compare trades across different account sizes and instruments on equal terms.
Import trades from any broker. Tradapt automatically calculates R-multiples, expectancy, and tracks whether your actual risk matches your intended risk on every trade.
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Automatic position sizing guidance and risk metrics in Tradapt.