Position Size Calculator for Trading

Use this free position size calculator to plan your trade risk before entering a position. Calculate how many units, shares, or contracts you can take based on your account size, risk percentage, entry price, stop loss, and target.

Best for

Choosing the right trade size before entering a stock, forex, crypto, CFD, or futures trade.

What you get

Position size, planned dollar loss, potential reward, risk/reward ratio, and break-even win rate.

Not for

Replacing your stop-loss plan, execution rules, liquidity checks, or trading strategy.

Formula

Position size = account risk amount / stop-loss distance

Example

A $25,000 account risking 1% with a $2 stop distance risks $250 and can take 125 units before fees.

Hexaplan verdict

Use this before every trade when stop distance changes.

Position size formula

Position size = account risk amount / stop-loss distance.

Account risk amount = account size x risk percentage. Stop-loss distance = the absolute difference between entry price and stop-loss price. Potential reward = position size x target distance. Risk/reward ratio = potential reward / planned risk.

Position sizing example

Suppose your account is $25,000 and you want to risk 1% on a trade. Your maximum planned loss is $250. If your entry is $100 and your stop loss is $98, your stop distance is $2. That means your position size is 125 units. If your target is $105, your potential reward is $625 and your risk/reward ratio is 2.5R.

What is position sizing?

Position sizing is the process of deciding how large a trade should be based on your account size, risk tolerance, entry price, and stop-loss level. Instead of choosing a random number of shares or contracts, position sizing starts with the amount you are willing to lose if the trade is wrong.

Why position size matters

Position size controls how much a single trade can damage your account. Two traders can take the same setup with the same entry and stop loss, but the trader using larger size has much higher drawdown risk. A position size calculator helps keep trade risk consistent across different setups.

How to use this position size calculator

Enter your account size.
Choose your risk per trade.
Enter your planned entry price.
Enter your stop-loss price.
Enter your target price.
Review the position size, dollar risk, reward, and risk/reward ratio.

Position size vs risk/reward

Position size tells you how much you can buy or sell. Risk/reward tells you whether the potential reward is large enough compared with the planned loss. A good trade plan should consider both.

Common position sizing mistakes

Using the same position size for every trade.
Ignoring stop-loss distance.
Increasing size after losses.
Forgetting commissions, spread, slippage, or funding costs.
Risking too much on correlated trades.

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FAQ

How do I calculate position size?

Multiply your account size by your risk percentage, then divide that risk amount by the distance between your entry price and stop loss.

What is 1% risk per trade?

1% risk per trade means your planned loss at the stop loss equals 1% of your account before fees, slippage, and commissions.

What is a good risk per trade?

Many traders use a fixed risk percentage such as 0.5%, 1%, or 2% per trade. The right amount depends on your strategy, drawdown tolerance, account size, and experience.

Does this calculator include fees and slippage?

No. The calculator estimates planned risk based on entry and stop-loss distance. You should manually account for spreads, commissions, slippage, and liquidity.

Can I use this for forex or futures?

Yes, but contract specifications, pip value, tick value, and leverage can change the result. For futures, use the Futures P&L Calculator when you need tick-based contract risk.

What happens if my stop loss is far away?

A wider stop loss reduces your position size if your risk percentage stays the same. This helps keep your dollar risk consistent across trades.

What is risk/reward ratio?

Risk/reward compares your planned loss with your potential profit. A 2.5R trade means the potential reward is 2.5 times the planned risk.