Lot Size Calculator
Learn how to calculate the right position size for your forex trades
What is Lot Size in Forex?
Lot size determines how many units of currency you buy or sell in a trade. Proper lot sizing is one of the most important aspects of risk management - it directly controls how much you stand to gain or lose.
Types of Lots in Forex
| Lot Type | Units | Lot Size | Pip Value (EUR/USD) |
|---|---|---|---|
| Standard | 100,000 | 1.00 | $10.00 |
| Mini | 10,000 | 0.10 | $1.00 |
| Micro | 1,000 | 0.01 | $0.10 |
| Nano | 100 | 0.001 | $0.01 |
How to Calculate Lot Size
The lot size formula combines your risk tolerance, stop loss distance, and pip value:
Lot Size = Risk Amount / (Stop Loss Pips x Pip Value)
Risk Amount = Account Balance x Risk Percentage
Stop Loss Pips = Distance from entry to stop loss
Pip Value = Value per pip for the currency pair
Lot Size Calculation Examples
Example 1: EUR/USD with 1% Risk
Given:
- Account: $10,000
- Risk: 1% ($100)
- Stop Loss: 50 pips
- Pip Value: $10/lot
Calculation:
$100 / (50 x $10)
= $100 / $500
= 0.20 lots
20,000 units (2 mini lots)
Example 2: GBP/USD with 2% Risk
Given:
- Account: $5,000
- Risk: 2% ($100)
- Stop Loss: 25 pips
- Pip Value: $10/lot
Calculation:
$100 / (25 x $10)
= $100 / $250
= 0.40 lots
40,000 units (4 mini lots)
The 1% Rule for Position Sizing
Most professional traders follow the 1% rule: never risk more than 1% of your account on a single trade. This ensures you can survive a string of losses without blowing your account.
1% Risk by Account Size
$1,000
Risk: $10
$5,000
Risk: $50
$10,000
Risk: $100
$50,000
Risk: $500
Common Lot Size Mistakes
- -Overleveraging - Using lot sizes too large for your account
- -Inconsistent sizing - Changing lot size based on emotion rather than math
- -Ignoring pip value - Not accounting for different pip values across pairs
- -Risking too much - Going above 2% risk per trade
Frequently Asked Questions
How do you calculate lot size in forex?
Lot Size = Risk Amount / (Stop Loss in Pips x Pip Value). For example, risking $100 with a 50 pip stop loss and $10 pip value: 100 / (50 x 10) = 0.20 lots.
What is a standard lot in forex?
A standard lot is 100,000 units of the base currency. A mini lot is 10,000 units (0.1 lots), and a micro lot is 1,000 units (0.01 lots).
What lot size should I use for a $10,000 account?
With a $10,000 account risking 1% ($100) per trade and a 50 pip stop loss on EUR/USD, you should use approximately 0.20 standard lots (20,000 units).
What is the 1% rule in forex?
The 1% rule means never risking more than 1% of your account on a single trade. For a $10,000 account, maximum risk per trade would be $100.
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Risk Disclosure: Trading involves substantial risk of loss and is not suitable for all investors. This content is for educational purposes only and does not constitute financial advice.
Last updated: December 2025