Free Position Size Calculator
Calculate the perfect trade size to manage risk and maximize consistency in your trading strategy.
Manage your Risk
How to Use the Position Size Calculator
How to use RiskLot?
1. Enter your Account size in your currency.
2. Choose the Risk percentage you are comfortable with.
3. Enter the Entry price.
4. Enter your Stop-Loss.
5. Enter your Take-Profit (optional)
6. Click Calculate & use the data!
Example:
💰 Account Size ($): $1000
⚠ Risk (%): 2%
📊 Entry Price ($): $100
📉 Stop Loss ($): $98
📈 Take Profit ($): $104
Position Size: 10.0 units
Visual: ⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛
Max Risk: $20.0
Account Portion: 2.0%
Risk to Reward: 1:2
What is a Position Size Calculator?
A position size calculator is a risk management tool that helps traders determine the exact number of units, shares, or lots to trade while limiting their risk to a specific percentage of their account.
It calculates the proper position size based on your account balance, chosen risk percentage (e.g., 1%), and stop-loss distance so you avoid overexposing your capital on any single trade.
On RiskLot, our free Python-powered calculator instantly shows you the precise units or lots corresponding to your risk percentage. Whether you trade forex, stocks, or crypto, it takes the guesswork out of position sizing.
How Position Sizing Works?
Position sizing is the process of deciding how large (or small) each trade should be based on your total account balance and risk tolerance.
The core idea is simple: never risk more than a small fixed percentage of your capital on any one trade, most professional traders use 0.5% to 2%.
The basic formula is:
Risk Amount = Account Balance × Risk Percentage
Position Size = Risk Amount ÷ (Stop-Loss Distance in price/pips/ticks)
Our calculator automates all of this for you, including adjustments for different instruments.
Example Calculation
Let’s say you have a $10,000 trading account and follow the common 1% risk rule. You want to trade EUR/USD with a stop-loss 50 pips away.
Risk per trade = $10,000 × 1% = $100
Asset price = $50
Stop-loss = $45
Position size = $100 ÷ $50 = 20 units.
With RiskLot, you just enter your account size, asset price, risk %, and stop-loss and the calculator instantly gives you the exact units. Try it above!
Common Mistakes Traders Make
Even experienced traders often get position sizing wrong. Here are the most common mistakes and how to avoid them:
- Risking too much per trade (e.g., 5–10% or more), one bad streak can wipe out your account.
- Trading based on “gut feeling” or conviction instead of math - always calculate first.
- Ignoring stop-losses or moving them further away to “give the trade room.”
- Revenge trading increasing position size after a loss to recover quickly.
- Not adjusting for account changes your risk % should be based on your current balance, not the starting one.
- Rounding up lot sizes “because it looks nicer”, even 0.03 extra lots can break your risk rules.
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