Example 1 — EUR/USD, SL 50 pips
- Account balance
- $5,000
- Risk
- 2%
- Instrument
- EUR/USD
- Stop Loss
- 50 pips
Risk amount = $100. Risk value per lot = 50 × $10 = $500, so lot size = 0.20 lot. Actual risk = $100.
Lot Size Calculator
Work out the right lot size from your account balance, the risk percentage you accept, and your stop loss distance, so risk per trade stays on target.
- Free
- No data stored
- Formula shown
Suggested lot size
0.10Mini
Actual risk 20.00 USD (2.00%)
Fairly high — aim for 1–2%
Below minimum
The calculated lot size is below 0.01, so the tool uses 0.01 lot instead, the typical broker minimum. This makes your actual risk higher than the target you set.
Risk too high
The risk percentage you set is above 10%, well beyond typical recommendations. Consider lowering it.
- Target risk amount (USD)
- 20.00
- Target risk amount (THB)
- 653.20
- Risk value per lot
- 200.00
- Pip value per lot
- 1.00
- Stop Loss (Pips)
- 200.0
- Total contract size (units)
- 10
Worked examples
Try it with real numbers
Example 2 — XAU/USD, SL $2.00
- Account balance
- $1,000
- Risk
- 2%
- Instrument
- XAU/USD
- Stop Loss
- $2.00 (= 200 pips)
Risk amount = $20. Risk value per lot = 200 × $1 = $200, so lot size = 0.10 lot. Actual risk = $20.
The formula
How to calculate lot size from risk
Risk amount (USD) = account balance × (risk % ÷ 100)
Risk value per lot = stop loss (pips) × pip value per lot
Lot size = risk amount (USD) ÷ risk value per lot — always rounded down to the nearest 0.01
Risk value per lot = stop loss (pips) × pip value per lot
Lot size = risk amount (USD) ÷ risk value per lot — always rounded down to the nearest 0.01
What each variable means:
- Account balance — All the funds in your trading account, in USD.
- Risk % — The share of your account balance you're willing to lose on a single trade. 1–2% is typical.
- Stop loss — The distance the price can move against you before the trade closes automatically, set in pips or price distance for gold and silver only.
- Pip value per lot — Uses the same formula as the Pip Calculator to convert stop loss into a risk value per lot.
The calculated lot size is always rounded down, never up or to the nearest value, because rounding up would push your actual risk past the target you set. If rounding down lands below 0.01, the tool shows "0.01 (minimum)" along with a warning that your actual risk will run higher than intended.
The 4 lot types
Lot sizes in forex and gold trading come in four tiers based on contract size. Pick the one that matches your account balance.
| Type | Lot size | Units (major pairs) | Approx. pip value | Best for |
|---|---|---|---|---|
| Standard | 1.00 | 100,000 units | $10 / pip | $10,000 and up |
| Mini | 0.10 | 10,000 units | $1 / pip | $1,000–$10,000 |
| Micro | 0.01 | 1,000 units | $0.10 / pip | $100–$1,000 |
| Nano | 0.001 | 100 units | $0.01 / pip | Under $100 |
Most brokers support a minimum of 0.01 lot (Micro). Nano lots are only available on some platforms, so this tool uses 0.01 as the calculation minimum.
How much risk per trade is reasonable
A common approach caps risk at 1–2% of your account per trade. Ten losing trades in a row at 2% risk each brings your account down by only about 18–20%, which still leaves room to recover. At 10% risk per trade, the same ten losses would wipe out nearly the entire account.
Mistakes that blow up your account
- Using the same lot size every time, no matter how wide or narrow the stop loss is, which lets some trades risk more than intended without you noticing.
- Moving the stop loss away from price to avoid taking a loss, which makes the actual risk many times larger than planned.
- Increasing lot size after a loss to average down faster, adding more risk at the worst possible moment.
- Ignoring the exchange rate on pairs not quoted in USD, which leads to a misjudged risk value.
FAQ
Frequently asked questions
Why is lot size always rounded down instead of to the nearest value or up
Because this tool's goal is to never risk more than you set. Rounding up, even slightly, pushes the actual risk above your plan, so it always rounds down for safety, even if that leaves actual risk a touch below target.
What should I do if the calculated lot size is below 0.01
You have three options: lower the risk percentage, add to your account balance, or tighten the stop loss if the technical setup allows it. If you still need to open at 0.01 lot, keep in mind the actual risk will run a bit above your target.
What's the difference between choosing stop loss as price distance versus pips
For gold and silver, many traders think in dollar distance, like SL $2.00, rather than in pips, so this tool converts automatically. Since 1 pip of XAU/USD equals $0.01, an SL of $2.00 works out to 200 pips.
What do the gauge colors in the result mean
Green means actual risk is 1% or under, gold means it's between 1–3%, and red means it's above 3%, well past typical recommendations. The gauge doesn't block the calculation. It's only there to prompt a second look.
What's the minimum account balance this tool accepts
The tool sets a minimum of $10 so the risk-percentage math still makes sense. In practice, most real trading accounts require a much higher minimum deposit.
Next steps
Related tools and lessons
Pip Calculator
Find the value of one pip for XAU/USD and major pairs, in USD and THB.
Example 1 lot XAU/USD = $1.00/pip
Open toolGold Price Converter
Convert the world spot price into the Thai gold-bar price per baht-weight, and back.
Example spot $2,400 @ 32.66 = 37,072 THB
Open toolLearn more about risk management in Chapter 04: Trading XAU/USD on a Forex Platform → · See the full curriculum →