Forex Position Size Calculator with Costs
Size a forex trade from equity, entry and stop prices. Include commission, conversion and the broker’s lot step before comparing the result with MT5.
How position sizing works
Risk budget = equity × risk percentage. Loss per lot = entry-to-stop distance × contract size × quote-to-account conversion + round-trip commission + extra cost pips × pip value per lot. Volume is rounded down to the broker’s lot step and capped by its maximum. A result below the minimum becomes zero; the calculator never rounds it up into a larger risk.
Use executable prices
Enter the expected buy ask or sell bid and the price at which the position would close. When those prices already include the spread, leave the extra spread allowance at zero to avoid counting it twice. A gap or a worse fill can exceed this planned loss. The calculator does not check available margin.
For most FX pairs one pip is 0.0001; for JPY quote pairs it is 0.01. Fractional platform points are not whole pips. Contract size is editable because the broker’s specification controls the actual exposure.
Currency conversion
ECB rates are daily reference rates against EUR, not live trade quotes. Quote-to-account conversion equals the account currency’s ECB rate divided by the quote currency’s ECB rate. For example, with EUR as the account currency and USD quoted at 1.10 per EUR, one USD converts to approximately 0.90909 EUR. Update the conversion at the time of your calculation.
Source: ECB reference rates and publication policy. Verify the result against MT5 order profit and symbol specifications.
For metals and indices, use the tick-value position calculator.
Frequently asked questions
Why is the lot size rounded down?
A broker only accepts its permitted lot increments. Rounding up can exceed your entered risk budget; a result below the broker minimum is therefore zero.
Does the calculation check available margin?
No. It estimates loss at the entered stop, including your cost inputs. Check available margin, contract size and current conversion in the trading platform separately.
Related tools and guides
Educational research, not personal investment advice. CFDs are leveraged products and can cause rapid losses. A calculation, indicator or stop cannot guarantee an account outcome.
How much is 0.01 lot in dollars?
0.01 lot is a volume, not a fixed dollar amount. If the EURUSD contract is 100,000 EUR per lot, 0.01 lot represents 1,000 EUR. At an illustrative price of 1.10000 USD per EUR, its notional value is 1,100 USD. That is different from your deposit, the margin required to open the position and the estimated loss at a stop.
- Pip value: assuming a pip is 0.0001 and the account currency is USD, 0.01 lot changes by 0.10 USD per pip.
- Planned stop loss: a 20-pip distance gives 2.00 USD before costs. Under the first worked example below, 7 USD round-trip commission per lot adds 0.07 USD and a 0.5-pip allowance adds 0.05 USD: 2.12 USD in total for 0.01 lot.
- Margin: this is a separate account/symbol calculation. The calculator above estimates stop loss including entered costs; it does not check available margin.
Check your broker's actual contract size, minimum volume and volume step in MT5's symbol specifications. MetaQuotes documents the contract and volume properties and OrderCalcMargin for margin estimates in account currency. A different symbol or account currency changes these amounts. All prices and costs here are hypothetical; a stop does not guarantee the execution price or final loss.
Use the lot size calculator with your entry, stop, account currency and costs, then compare its rounded volume with the broker's specifications.
Forex lot size examples with commission and currency conversion
A useful check is to calculate the loss for one lot first, then apply the account-currency budget and round down to the permitted volume step. The examples below use invented prices, conversion rates and contract terms. They are arithmetic illustrations, not current broker specifications or suggested trades. The 0.5% input demonstrates the calculation; it is not a recommended risk percentage.
For all three examples, assume account equity of 10,000 in the stated account currency, an entered budget of 0.5% (50 in that currency), 100,000 base-currency units per lot, a 0.01 lot step, a 0.01 lot minimum and a 100 lot maximum. Commission is the total for opening and closing one lot. The additional 0.5-pip allowance represents costs beyond the entered executable entry and exit prices; do not add spread again if those prices already capture it.
| Input | EURUSD / USD account | USDJPY / USD account | EURUSD / EUR account |
|---|---|---|---|
| Planned entry | 1.10000 | 150.00 | 1.10000 |
| Stop price | 1.09800 | 149.80 | 1.09800 |
| Pip size | 0.0001 | 0.01 | 0.0001 |
| Quote → account conversion | 1 USD per USD | 1 ÷ 150 USD per JPY | 0.90 EUR per USD |
| Round-trip commission per lot | 7 USD | 7 USD | 6 EUR |
| Additional cost allowance | 0.5 pip | 0.5 pip | 0.5 pip |
EURUSD: include costs before rounding the lot size
The price distance is 0.00200, or 20 pips under the stated convention. One lot loses 0.00200 × 100,000 × 1 = 200 USD at the entered stop. The pip value is 10 USD per lot, so the allowance adds 5 USD. Including commission gives 200 + 7 + 5 = 212 USD per lot.
The unrounded size is 50 ÷ 212 = 0.235849… lots. Rounding down to 0.01 gives 0.23 lots, with an estimated loss including the entered costs of 48.76 USD. Rounding up to 0.24 would give 50.88 USD and exceed the entered budget.
USDJPY: convert the quote-currency loss into account currency
The distance is 0.20, or 20 pips here. The one-lot price loss is 20,000 JPY. Using the fixed illustrative conversion of 1 ÷ 150 gives 133.333333… USD. One pip is 6.666666… USD per lot, so the 0.5-pip allowance adds 3.333333… USD. Including 7 USD commission gives 143.666666… USD per lot.
50 ÷ 143.666666… = 0.348027… lots, which rounds down to 0.34 lots. The estimated loss is 48.85 USD when displayed to two decimals. This example holds the conversion rate constant; a different rate at the planned exit changes the result.
EUR account: enter commission in EUR as well
The EURUSD price loss is 200 USD per lot. At the hypothetical conversion of 0.90 EUR per USD, that is 180 EUR. The pip value becomes 9 EUR per lot, and the allowance adds 4.50 EUR. With 6 EUR commission, the total is 180 + 6 + 4.50 = 190.50 EUR per lot.
50 ÷ 190.50 = 0.262467… lots, so the rounded size is 0.26 lots and the estimated loss is 49.53 EUR. Entering USD commission in an EUR field would mix currencies and invalidate this check.
Why can the result be zero?
Using the first example, the minimum 0.01 lot would represent 2.12 USD of estimated loss. If the entered budget were only 1 USD, even that minimum would exceed it. A zero result means there is no permitted positive volume within those inputs; increasing the volume to the minimum would defeat the calculation.
These estimates do not check available margin or guarantee a stop fill. For a platform comparison, use the same symbol, direction, volume, entry and stop. MetaQuotes documents OrderCalcProfit as a pre-evaluation in account currency; compare the price component separately from the costs added here.
Continue with the trading cost calculator or the gold and index tick-value calculator. If you are researching an account, compare country eligibility, platforms and costs. Broker reviews may contain marked affiliate links from which we can receive a commission.