Step-by-Step Guide
How to Calculate
Position Size
in Forex
Position sizing determines how many lots you trade so that a losing trade costs exactly your planned risk — no more. This is the single most important calculation in funded account trading.
POSITION SIZER
Multi-Asset Protocol
Your current account equity or challenge balance
Trade90 Safety System: 0.5% max per trade
Your planned trade entry price
Price where your trade idea is invalidated
Your target — used to calculate R:R ratio
Recommended Position
✓ SAFEStandard Lots
Total Risk
$500.00
R:R Ratio
1:1.00
Stop Pips
50.0
Define Your Dollar Risk
Before you calculate a lot size, decide what percentage of your account you are willing to lose on this trade. This is your risk per trade.
Dollar Risk = Account Balance × (Risk% ÷ 100)
$100,000 × (0.5 ÷ 100) = $500
Trade90 Safety System
For funded account challenges, cap your risk at 0.5% per trade. At 0.5%, five consecutive losses only cost 2.5% — within every major prop firm's daily drawdown limit.
Measure Your Stop Loss in Pips
Place your stop loss at the level where your trade idea is genuinely wrong — outside normal intraday noise. Then measure the distance from entry to stop in pips.
Stop Pips = |Entry − Stop Loss| ÷ Pip Size
|1.08500 − 1.08250| ÷ 0.0001 = 25 pips
| Instrument | Pip Size | Example 25-pip stop |
|---|---|---|
| EUR/USD, GBP/USD, AUD/USD | 0.0001 | 0.0025 price distance |
| USD/JPY, EUR/JPY | 0.01 | 0.25 price distance |
| Gold (XAU/USD) | 0.1 | 2.5 price distance |
| NAS100 / US30 | 1.0 | 25 point distance |
| Bitcoin (BTC/USD) | 1.0 | 25 point distance |
Find the Pip Value for Your Instrument
Pip value is how much one pip of movement is worth in dollars per standard lot. It varies by instrument and determines the dollar cost of your stop loss distance.
Calculate Your Lot Size
Divide your dollar risk by the stop loss distance multiplied by the pip value. The result is your position size in standard lots.
Lot Size = Dollar Risk ÷ (Stop Pips × Pip Value per Lot)
$500 ÷ (25 × $10) = 2.00 lots
EUR/USD
| Balance | $100,000 |
| Risk | 0.5% |
| Stop | 25 pips |
| Pip Value | $10/lot |
| Result | 2.00 lots |
Gold (XAU/USD)
| Balance | $100,000 |
| Risk | 0.5% |
| Stop | 150 pips |
| Pip Value | $10/0.1 lot |
| Result | 0.33 lots |
NAS100
| Balance | $100,000 |
| Risk | 0.5% |
| Stop | 50 pts |
| Pip Value | $1/0.1 lot |
| Result | 1.00 lots |
GBP/USD
| Balance | $50,000 |
| Risk | 0.5% |
| Stop | 30 pips |
| Pip Value | $10/lot |
| Result | 0.83 lots |