Position Size Calculator — Forex, Stocks & Crypto
Calculate your exact position size in lots, shares, or units — enter your account balance, risk per trade (%), and stop loss distance to get the mathematically correct lot size instantly. Works for forex pairs, US stocks, and crypto assets. No guesswork, no spreadsheet.
Updated · Reviewed by Foysal Mostafa
Asset Class
EUR/USD = $10, USD/JPY ≈ $9.50
Results
Risk Amount
100.00
USD
Standard Lots
0.50
lots
Mini Lots
5.00
mini
Micro Lots
50.0
micro
Units
50,000
units
✓ Conservative — recommended for most traders
Why Use the Position Size Calculator?
Most traders who blow their accounts don't lose because their analysis is wrong — they lose because they trade too large. A single oversized trade can wipe out weeks of gains in minutes. This position size calculator removes the guesswork: enter your account balance, define your maximum risk per trade (typically 1–2%), set your stop loss distance, and get the mathematically exact position size every time. Professional traders use a position size calculator before every single trade — it is the foundation of all serious risk management.
Formula Used
Position Size = (Account Balance × Risk %) ÷ (Stop Loss in pips × Pip Value)Worked Example
Example: $10,000 account, 1% risk ($100), 20-pip stop on EUR/USD (pip value = $10/lot). Position Size = $100 ÷ (20 × $10) = 0.50 lots. At 0.50 lots your maximum loss on this trade is exactly $100 — 1% of your account.
How to Use the Position Size Calculator — Step by Step
- 1
Select your asset class
Choose Forex, Stocks, or Crypto depending on the market you are trading. Each asset class uses a different position sizing formula.
- 2
Enter your account balance
Type your total trading account balance in USD. This is the total capital in your trading account, not just the free margin.
- 3
Set your risk percentage
Enter the percentage of your account you are willing to risk on this single trade. Professional traders typically use 1–2% per trade.
- 4
Enter your stop loss distance
For forex, enter the number of pips to your stop loss. For stocks and crypto, enter the dollar distance from entry to stop loss price.
- 5
Read your position size
The calculator instantly shows your ideal position size in lots (forex), shares (stocks), or coins (crypto). Use this exact size when placing your trade.
What Your Position Size Calculator Results Mean
Position Size (Lots)
The exact number of standard lots to trade. 1.0 = standard lot (100,000 units), 0.1 = mini lot (10,000 units), 0.01 = micro lot (1,000 units). Use this number directly in your broker's order ticket.
Dollar Risk
The exact dollar amount you will lose if price hits your stop loss. This should match your pre-defined risk per trade (e.g. 1% of account = $100 on a $10,000 account).
Units
The raw number of currency units or shares to trade. For forex: multiply lots by 100,000. For stocks: this is your share count. For crypto: this is the number of coins.
Position Size Calculator — Frequently Asked Questions
Q.What is position sizing in trading?
Position sizing determines how many units of an asset to trade based on your risk tolerance. Proper position sizing ensures no single trade can wipe out more than your defined risk per trade (typically 1–2% of account balance).
Q.What is the 1% rule in trading?
The 1% rule means never risking more than 1% of your total account balance on a single trade. If you have a $10,000 account, your maximum loss per trade should be $100.
Q.How do I calculate lot size in forex?
Lot size = (Account Balance × Risk %) ÷ (Stop Loss in pips × Pip Value per lot). For a standard lot in EUR/USD, each pip is worth $10. If you risk $100 with a 10-pip stop loss, your lot size = $100 ÷ (10 × $10) = 1 lot.
Q.Does this calculator work for crypto?
Yes. For crypto, enter your account balance in USD, your risk percentage, and your stop-loss distance in dollars. The calculator returns how many units (e.g. BTC, ETH) you should buy.
Q.What percentage of my account should I risk per trade?
Most professional traders risk 1–2% of their account per trade. At 1% risk, you can absorb 50+ consecutive losses before losing half your account. Beginners should start at 0.5–1%. Never risk more than 2% per trade — even at 2% risk, just 10 losing trades in a row cost you 18% of your account.
About the Author
Forex Trader & Software Developer · Founder, TradeCalc
Active forex trader since 2019, specializing in risk management and systematic position sizing. Built TradeCalc to replace manual spreadsheets used in live trading. Every calculator is cross-verified against broker platforms before publishing.
More Forex Calculators
Margin Calculator
Calculate required margin for any forex or CFD trade. Enter your leverage, lot size, and currency pair to see how much margin you need to open a position.
Kelly Criterion Calculator
Calculate the mathematically optimal position size for your trading strategy using the Kelly Criterion formula. Enter win rate and R:R ratio to get full and half Kelly percentages.
Profit / Loss Calculator
Calculate your exact trading profit or loss before placing a trade. Works for forex, stocks, and crypto. Enter entry price, exit price, and position size.
Risk / Reward Calculator
Free risk reward ratio calculator — enter entry, stop loss, and take profit to instantly see your R:R ratio and the exact win rate needed to be profitable.