Risk Warning: CFDs and forex trading involve significant risk of loss. Leveraged products can result in losses exceeding your deposit. This calculator is for educational purposes only and does not constitute financial advice.
Forex Lot Size Calculator
Calculate your forex position size in standard lots, mini lots, micro lots, and raw units. Enter your account balance, risk percentage, and stop-loss distance to find the precise lot size for any pair.
Formula
Four-step formula
Risk Amount
Risk Amount = Balance × (Risk% ÷ 100)
Pip Value/Lot
Pip Value/Lot = Pip Size × 100,000 × Quote→Account Rate
Standard Lots
Lots = Risk Amount ÷ (Stop Pips × Pip Value/Lot)
Lot Conversions
Mini Lots = Lots × 10 · Micro Lots = Lots × 100 · Units = Lots × 100,000
Pip Size = 0.0001 for most pairs · 0.01 for JPY quote pairs
Worked Example
Given
$10,000 account · 1% risk · 20-pip stop-loss · EUR/USD · USD account · rate = 1.0
- Risk Amount
- $10,000 × 1% = $100
- Pip Value / Lot
- 0.0001 × 100,000 × 1.0 = $10.00
- Standard Lots
- $100 ÷ (20 × $10) = 0.5 lots
- Mini Lots
- 0.5 × 10 = 5 mini lots
- Units
- 0.5 × 100,000 = 50,000 units
Frequently Asked Questions
- What is a lot in forex trading?
- A lot is the standard unit of trade size in forex. One standard lot = 100,000 units of the base currency. Brokers also offer mini lots (10,000 units = 0.1 lots), micro lots (1,000 units = 0.01 lots), and sometimes nano lots (100 units = 0.001 lots). Trading in standard lots means each pip is worth approximately $10 for major pairs with a USD account.
- What is the difference between lot size and position size?
- They refer to the same thing from different angles. "Lot size" is the broker-specific unit (0.5 lots). "Position size" is the underlying unit count (50,000 units). The Lot Size Calculator shows both, along with mini lots and micro lots, so you can enter the right value regardless of how your broker's platform labels the field.
- Why does lot size change with the stop-loss distance?
- Risk-adjusted lot sizing keeps your dollar risk constant regardless of where you place your stop. A wider stop means fewer lots (smaller position) so the same pip distance still only costs you the same dollar amount. A 50-pip stop with $100 risk and $10/pip pip value → 0.20 lots. A 20-pip stop with the same risk → 0.50 lots.
- What lot size should I use as a beginner?
- Most risk management guides recommend starting with micro lots (0.01) or mini lots (0.1) until you have a proven edge. Risk no more than 1–2% of your account per trade. On a $1,000 account at 1% risk, that is $10 per trade. With a 20-pip stop on EUR/USD, you would trade 0.05 lots (5 micro lots).
- Does the engine round the lot size output?
- No — the calculator returns the mathematically exact lot size as a raw decimal. Most retail brokers round to the nearest 0.01 lots. You should round the output down to your broker's minimum increment to avoid accidentally opening a larger position than your risk management allows.