Account balance ($)
Risk per trade (%)
Entry price
Stop loss price
Pip value ($/pip/lot)
enter trade details
Result
Trading Decision
Don't round up
This is your maximum position for this trade at your chosen risk %. If it rounds to a very small number, either your risk amount is too small for this stop distance, or your pip-value entry is too high — check both before widening the stop or rounding the lot size up.
Below broker minimum?
If the result is smaller than your broker's minimum lot increment (often 0.01), reduce your risk % or widen your stop loss rather than rounding up and quietly accepting extra risk.
Only accurate if the stop holds
This figure assumes your stop loss is honored exactly as entered. If you tend to move stops further away mid-trade, your real risk is higher than this result shows.
➜ Next step: Confirm the pip value assumption above with the Pip Value Calculator for your exact pair, then check the Margin Calculator to make sure your broker's margin requirement doesn't limit this position before you enter.
About lot size calculation
Risk management
Never risk more than 1–2% per trade. This calculator ensures your position size matches your risk tolerance.
Pip value
For standard EUR/USD lots, pip value is ~$10. For gold (XAUUSD), use $1 per 0.01 move = $100/lot for $1 move.
Formula
Lot size = Risk Amount / (Stop Loss in pips × Pip Value per lot)
How to Use the Lot Size Calculator
- Enter your account balance — your total equity including open positions.
- Set risk percentage — the percentage of account to risk on this trade. Use 0.5–1% for prop firm accounts, 1–2% for personal accounts.
- Enter stop loss in pips — the distance from your entry price to your stop loss. This is determined by your chart analysis, not by your desired lot size.
- Select currency pair — choose your instrument. The calculator uses the correct pip value for each pair automatically.
- Read your lot size — the exact position size that risks the percentage you specified. Use this number precisely in your broker's order entry.
🔑 Golden rule: Always calculate lot size AFTER placing your stop loss on the chart. Your stop loss location is determined by market structure — support, resistance, swing highs/lows. Your lot size is then calculated to risk exactly your chosen percentage at that stop distance.
Understanding Lot Sizes
📦 Standard Lot
100,000 units of base currency. On EURUSD, 1 standard lot = $10 per pip. This is the largest standard position size — used by institutional traders and well-funded retail accounts.
📦 Mini Lot
10,000 units = 0.1 lots. $1 per pip on EURUSD. Suitable for accounts of $1,000–$10,000 with proper risk management.
📦 Micro Lot
1,000 units = 0.01 lots. $0.10 per pip on EURUSD. Used for very small accounts or for fine-tuning position sizes to the exact cent of risk.
💰 Pip Value
The dollar value of a 1-pip move per lot. Varies by pair and account currency. EURUSD: $10/pip/lot. USDJPY: ~$9.10/pip/lot. XAUUSD (Gold): $10/pip/lot but pips are $0.01 price moves.
📐 The Formula
Lot Size = (Account × Risk%) ÷ (Stop Loss Pips × Pip Value Per Lot). Example: $10,000 × 1% ÷ (20 pips × $10) = $100 ÷ $200 = 0.5 lots.
⚠️ Prop Firm Context
On a $100K prop firm account with 5% daily DD and 1% risk per trade, you can sustain 5 consecutive losing trades before breaching the daily limit. This is why 0.5% risk is recommended — giving 10 losing trades of buffer.
Lot Size and Risk Management
Why lot size is your most important decision
Every other aspect of trading — entry signals, indicators, news analysis — is secondary to position sizing. A trader with a mediocre strategy and perfect position sizing will outperform a trader with an excellent strategy and poor position sizing over time. Lot size directly controls your survival during losing streaks.
Adjusting for volatility
During high-volatility periods (major news events, market open/close), consider reducing your normal lot size by 30–50%. Wider spreads, slippage, and unpredictable price action mean your actual risk can be significantly higher than your calculated risk. Consistent traders reduce size in uncertain conditions.
Scaling into positions
Some traders split their intended position into 2–3 entries, adding to the position as it moves in their direction. If your normal size is 1 lot, enter 0.5 lots at the initial signal and add 0.5 lots after confirmation. This reduces the risk of full-size entry at a poor price while maintaining upside participation.
📊 Simple sizing rule for beginners: Use 1% risk per trade until you have 100 live trades recorded. After 100 trades, calculate your actual win rate and expectancy. Only then consider adjusting risk percentage based on your proven edge.
Lot Size Formula
Lot Size = Risk Amount ÷ (Stop Loss in Pips × Pip Value per Lot), where Risk Amount = Balance × Risk %
Risk Amount
The dollar amount you're willing to lose on this trade — your account balance multiplied by your chosen risk percentage.
Stop Loss in Pips
The distance between entry and stop-loss price, converted into pips using the pair's pip size (0.0001 for most pairs, 0.01 for JPY pairs and gold) — not the raw price difference.
Pip Value per Lot
How much one pip of movement is worth for one standard lot of the pair — roughly $10 for most USD-quoted pairs, but check the exact figure with the Pip Value Calculator.
Worked example
$10,000 balance, 1% risk, EUR/USD entry 1.2500 → stop loss 1.2450: risk amount = $100; price distance 0.0050 ÷ 0.0001 pip size = 50 pips; lot size = 100 ÷ (50 × $10) = 0.20 lots.
Avoid These Mistakes
Confusing risk amount with lot size
Risk Amount is your maximum dollar loss; Lot Size is how many units that translates to given your stop distance. An error in the stop distance breaks the whole result, not just one line.
One lot size for every trade
Using the same lot size regardless of stop-loss distance. A wider stop at the same risk % always means a smaller lot size, and vice versa — recalculate every trade.
Wrong pair selected
Pip size differs by pair (0.0001 vs 0.01 for JPY/gold). Picking the wrong one in the dropdown silently produces a wrong lot size even if every other input is correct.
Guessing pip value
Leaving "Pip value" at a rough default like $10 for every pair. Pip value per lot varies by pair and account currency — check the exact figure with the Pip Value Calculator instead of assuming.
Frequently Asked Questions
What is a lot in forex?
1 standard lot = 100,000 units of base currency. 1 mini lot = 10,000 units. 1 micro lot = 1,000 units. Most retail brokers allow trading in 0.01 lot increments.
Why is position sizing critical?
Position sizing determines how much you lose on a bad trade. Risking 1% per trade means even 50 consecutive losses only reduces the account by ~40%. Risking 5% makes 20 losses catastrophic.
What is the 1% risk rule?
Risk no more than 1–2% of account balance per trade. On a $10,000 account, 1% = $100 maximum loss. This ensures a long losing streak doesn't wipe the account.
Why does the currency pair matter for lot size?
The pair determines the pip size used to convert your entry/stop-loss price distance into an actual pip count — 0.0001 for most pairs but 0.01 for JPY pairs and gold. Using the wrong pip size overstates or understates your stop distance and produces an incorrect lot size.
References
🏛️ U.S. NFA
Position sizing and risk-disclosure guidance for retail forex — nfa.futures.org
🇪🇺 ESMA
EU retail leverage and risk-management framework — esma.europa.eu
📄 Broker contract specs
Exact pip value per lot varies slightly by broker and account currency — confirm against your broker's contract specification sheet before sizing a real position.
Last updated: 11 July 2026 · Formulas use standard 100,000-unit contract sizing unless your broker specifies otherwise.