Position Size & Risk Calculator
Size any trade to a fixed risk. Enter your balance, risk percentage, entry, and stop-loss to get the exact position size, implied leverage, and risk:reward. No signup, runs entirely in your browser.
How the Position Size Calculator Works
- 1Enter your account balance and the percentage you want to risk on this trade — 1% is the common default.
- 2Enter your entry price and your stop-loss price. The distance between them defines your risk per unit.
- 3Read the position size in units, plus the dollar amount at risk, position value, and implied leverage.
- 4Optionally add a take-profit price to see your risk:reward ratio before committing to the trade.
Worked Example: Sizing a Bitcoin Trade to 1% Risk
You have a $10,000 account and follow the 1% rule, so you are willing to lose $100 on this trade. You want to go long Bitcoin at an entry of $60,000 with a stop-loss at $58,000. Your risk per unit is the distance to the stop: $60,000 − $58,000 = $2,000 per coin. Position size = risk amount ÷ risk per unit = $100 ÷ $2,000 = 0.05 BTC. That position is worth 0.05 × $60,000 = $3,000, which is 0.3× your account — no leverage needed.
The power of sizing this way is that the outcome is fixed in advance: if price hits your $58,000 stop, you lose exactly $100 (1%), regardless of how volatile Bitcoin is. Now add a take-profit at $64,000. Your reward is 0.05 × ($64,000 − $60,000) = $200, giving a risk:reward of 1:2 — you stand to make twice what you risk, so you only need to be right about a third of the time to come out ahead. Tighten the stop to $59,500 and the calculator shows the position size jumping to 0.2 BTC and leverage rising to 1.2× — a vivid reminder that a tighter stop means a bigger position for the same dollar risk.
Risk Management Tips
Fix your risk, not your size
Always decide the dollar amount you will risk first, then let the stop distance determine the position size. Never pick a round position size and back into the risk — that is how accounts blow up on a single volatile candle.
Set the stop where you are wrong
Place your stop-loss at the price that invalidates your trade idea (below support, above resistance), not at an arbitrary dollar amount. The calculator then sizes the position around that logical level.
Watch the implied leverage
If the tool shows high leverage, your stop is very tight relative to your risk budget. A wick can stop you out prematurely. Widen the stop or lower the risk percentage to keep leverage reasonable.
Demand a worthwhile reward
Add your take-profit and check the risk:reward. Many traders skip any setup below 1:1.5. A good ratio lets you be wrong more often than right and still grow the account.
Account for fees and slippage
Exchange fees and slippage widen your real risk slightly beyond the stop distance. On tight scalps, subtract a little extra from your risk budget so a filled stop does not exceed your intended loss.
Keep total exposure in check
Sizing each trade to 1% is only half the job. If you hold five correlated positions all risking 1%, a market-wide move can cost 5% at once. Cap your combined open risk, not just per-trade risk.
Frequently Asked Questions
How is position size calculated?
Position size is the amount you risk divided by your risk per unit. First, the risk amount is your account balance times your risk percentage (e.g. $10,000 × 1% = $100). The risk per unit is the distance between your entry and stop-loss price. Position size in units = risk amount ÷ risk per unit. This guarantees that if the stop is hit, you lose exactly the amount you chose to risk — no more.
What risk percentage should I use per trade?
Most professional traders risk 0.5%–2% of their account on any single trade. The classic rule of thumb is 1%. Risking 1% means a losing streak of 10 trades costs about 10% of your account, which is recoverable. Risking 10% per trade means the same streak nearly wipes you out. Smaller risk per trade is the single biggest factor in surviving long enough to be profitable.
How does the calculator handle long vs short trades?
It detects direction automatically from your prices. If the stop-loss is below the entry, it is a long (you profit when price rises); if the stop is above the entry, it is a short. The math uses the absolute distance between entry and stop, so it works identically for both directions. The take-profit is only counted when it sits on the profitable side of your entry.
What does implied leverage mean?
Implied leverage is your total position value divided by your account balance. If the calculator says 3×, it means the position is three times larger than your account, so you would need 3× leverage (or margin) to open it. A high number is a signal that your stop is very tight relative to your risk budget — widen the stop or lower the risk percentage to bring it down.
What is a good risk:reward ratio?
Enter a take-profit price and the calculator shows your risk:reward. A ratio of 1:2 means you stand to make twice what you risk. With a 1:2 ratio you only need to win about 34% of trades to break even; at 1:1 you need to win over 50%. Many traders require at least 1:1.5 or 1:2 before taking a trade, so the reward justifies the risk.
Does this work for crypto, forex, and stocks?
Yes. The math is asset-agnostic — it works for any instrument where you have an entry price and a stop-loss price. For crypto and stocks the "units" are coins or shares. For forex you can treat units as the base currency amount, then divide by the contract size to get lots. Just keep all prices in the same currency.
Is my data stored anywhere?
No. Every calculation runs entirely in your browser with JavaScript. Nothing you type — account balance, prices, or risk settings — is ever sent to a server or stored.