Position Size Calculator

How Position Sizing Works

Position sizing is the process of determining how many lots to trade based on the amount of money you're willing to risk. Instead of guessing or using a fixed lot size for every trade, you calculate the position size that keeps your risk consistent.

The formula is straightforward: divide your risk amount by the dollar value of your stop loss distance.

For a $10,000 account with 2% risk ($200) and a 25-pip stop on EUR/USD ($10/pip): 200 ÷ (25 × 10) = 0.80 lots = 8 mini lots = 80,000 units.

Choosing Your Risk Percentage

The risk percentage is the fraction of your account you're willing to lose if the trade hits your stop loss. Professional traders typically risk 0.5% to 2% per trade. Higher percentages mean faster growth but also faster drawdowns.

A 1% risk on a $50,000 account means a $500 loss per losing trade. At that rate, you could lose 100 trades in a row before blowing the account — statistically near impossible with a trading edge. At 10% risk per trade, 10 consecutive losses would wipe you out.

Stop Loss and Pip Value

Two factors determine how many lots you can trade: your stop loss distance and the pip value of the pair. A wider stop loss means fewer lots for the same risk amount. A pair with a higher pip value per lot also means fewer lots.

For example, EUR/USD has a pip value of $10 per standard lot, while USD/JPY has approximately $6.50 per pip at 150.00. With the same $200 risk and 25-pip stop: EUR/USD = 200/(25×10) = 0.80 lots, USD/JPY = 200/(25×6.50) = 1.23 lots.

Get the exact pip value for your pair using the pip calculator before calculating position size.

Account Currency Considerations

If your account currency differs from the quote currency of the pair you're trading, pip values must be converted. A trader with a EUR account trading GBP/JPY needs two conversions: first from JPY to USD, then from USD to EUR. The calculator above handles this by asking for the current exchange rate when needed.

Lot Types Reference

Frequently Asked Questions

How do you calculate forex position size?

Position Size (lots) = (Account Balance × Risk %) / (Stop Loss in Pips × Pip Value per Lot). For a $10,000 account risking 2% ($200) with a 25-pip stop on EUR/USD ($10/pip): $200 / (25 × $10) = 0.8 lots. The calculator above computes this instantly for any pair and account currency.

What is the 2% rule in forex?

The 2% rule means you never risk more than 2% of your account on a single trade. On a $10,000 account, that's $200 max risk. If you have a 25-pip stop, your position size is automatically limited to 0.8 lots. Following this rule protects your account from a string of losses.

How many lots should I trade with a $1,000 account?

With $1,000 and 2% risk ($20), trading EUR/USD with a 20-pip stop: $20 / (20 × $10) = 0.1 lots (1 mini lot). With a wider 40-pip stop: $20 / (40 × $10) = 0.05 lots (5 micro lots). The position size adapts to your stop distance.

Does position size change with account currency?

Yes. If your account is in EUR and you trade EUR/USD, the pip value of $10 must be converted to EUR at the current rate (approximately €9.09 at 1.10). This changes the lot size calculation. The calculator handles this when you select your account currency and provide the exchange rate.