By Volodymyr Kravchenko Formula reviewed 13 Oct 2026

Prop Firm Lot Size and Daily Loss Calculator

Work out the lot size for a trade and see how much of today's loss allowance one stop-out would use, before you place it.

Lot size = (daily starting equity x risk %) / (stop distance x multiplier), rounded down to 0.01 lot. The calculator then compares the amount at risk with the daily loss allowance still left: up to 30% is safe, up to 60% a warning, above that danger. Enter your account limits, pick the instrument, then your entry, stop and target. It is an educational planning tool, not a trading signal.

The prices loaded here are round example numbers, not current market prices. Replace them with your own entry, stop and target. USD account, USD-quoted instruments.

Account preset

Account

Starting balance

The size of the account at the start

Daily starting equity

Equity at the start of today's trading day

Daily loss limit

Overall loss limit

Loss already taken todayoptional

Lowers the daily allowance left. Leave empty at the start of the day.

Limits and how they are measured differ by programme (FTMO's 1-Step has a 3% daily limit, for example). The presets are the 2-step limits from each firm's published rules: pick Custom Account for any other.

Trade

Instrument and multiplier

Contract sizes differ between brokers (gold is often 100 oz, oil 1,000 barrels or 100). Check yours, then use Custom if it differs.

Risk per trade0.5%

Risk %

Slider range 0.25% to 2% of daily starting equity. This tool shows the consequence of a number; it does not recommend one.

Entry price

Stop loss price

Take profit priceoptional

Recommended lot size

1.00lots

Rounded down to 0.01. If the stop is hit you lose about $500.00. Exact figure: 1.0000 lots.

SAFE

A stop-out would use 10.0% of the $5,000.00 daily allowance that is left.

Thresholds: up to 30% of the allowance is safe, up to 60% is a warning, above 60% is danger.

For your account: if this stop is hit you lose about $500.00 and keep about $4,500.00 of today's allowance and $9,500.00 overall. Check these before you enter, not after.

Risk amount: $500.00; Equity x risk %
Max allowed daily loss: $5,000.00; Equity x daily limit %
Daily allowance left: $5,000.00; Minus any loss taken today
Overall allowance left: $10,000.00; Equity floor $90,000.00
Stop loss distance: 5; Long trade
Risk to reward: 1 : 2.00; About $1,000.00 if the target is hit

Trading on a Challenge?

Read FundingPips's current rules and account types on its own site before you pay a fee.

Code

MARLIN

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Pressing the button also copies the code. Check the current offer and terms on FundingPips's site. Evaluations carry fees; the accounts are simulated and results are not guaranteed.

Need a broker for your own account?

Compare FxPro's current spreads and commissions on its own site. They change with the market and the account type.

See FxPro's current spreads

CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. Your capital is at risk.

Disclosure: these are affiliate links. We may earn a commission if you use them, at no extra cost to you. It does not change how the calculator works.

Educational planning tool, not investment advice and not a trading signal. Spread, slippage, gaps over the stop, commission and swaps are not included, so a real loss can be larger than the figure shown. Each firm sets its own way of measuring the daily and overall limits: read its rules before you trade.

How the calculation works

Risk amount. Daily starting equity x risk % / 100.
Max allowed daily loss. Daily starting equity x daily loss limit % / 100. Loss already taken today is subtracted to give the allowance left.
Stop distance. |entry - stop loss|, in price units. It is the same for a long or a short trade.
Lots. Risk amount / (stop distance x multiplier), rounded down to 0.01.
Risk to reward. 1 : |take profit - entry| / stop distance.
Overall limit. The equity floor is the starting balance x (100 - overall limit %) / 100. A stop that would take equity to the floor is shown as danger, whatever the daily figure says.

Worked example with hypothetical numbers, not market prices: a $100,000 account, 0.5% risk, gold entry 2,000.00, stop 1,995.00. Risk = $500. Distance = 5.00. At 100 oz per lot: 500 / (5 x 100) = 1.00 lot. Against a 5% daily limit ($5,000) that stop uses 10% of the allowance: safe.

What the status badge means

Badge	Share of daily allowance	In plain words
Safe	Up to 30% of the daily allowance left	One stop-out leaves most of today's room.
Warning	Over 30% and up to 60%	One stop-out takes a large part of today's room.
Danger	Over 60%, or the stop would reach the overall limit	One or two losses could end the day, or the account.

The 30% and 60% lines are Marlin's planning thresholds. They are not firm rules and not a recommendation of how much to risk.

Assumptions and limitations

USD account and USD-quoted instruments only (gold, oil, EURUSD, GBPUSD). Pairs such as USDJPY need a currency conversion that this tool does not do.
Each firm measures the daily and overall loss in its own way (balance or equity, static or trailing). Use the drawdown calculator for a firm's published formula and the comparison page for the rules.
Spread, slippage, gaps, commission and swaps are not modelled. A real loss can exceed the figure shown.
News-time rules can restrict trading around releases: see the news trading rules.
Prop firm accounts are simulated and evaluation fees can be lost. Nothing here promises a pass or a profit.

AdLooking for a funded account to size for?

This calculator uses published limits. FTMO states the current rules for each account type on its own site: check them before you choose a programme. Evaluation fees apply and nothing here promises a pass or a profit.

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Disclosure: Some links on this website are affiliate links. If you use them, we may receive compensation at no additional cost to you. This does not determine our editorial analysis, reviews or comparisons.

AdComparing funded programmes?

FundingPips states the current rules for each programme on its own site: check the limits before you choose. Evaluation fees apply and nothing here promises a pass or a profit.

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Compare published daily and overall loss limits · News trading rules

Managing leverage Your leverage is set by your risk and your stop, not by the broker's maximum.

Effective leverage = risk per trade % ÷ stop distance %. Size the position from the risk first and the leverage follows.

1% risk, stop 1% away: position about 1 times the account.
1% risk, stop 0.5% away: about 2 times.
1% risk, stop 0.25% away: about 4 times. A tight stop raises leverage, so check it before you enter.

Example on a $10,000 account: 1% is $100. With a stop 0.5% away the position is $100 ÷ 0.005 = $20,000, which is 2 times the account (arithmetic, not a forecast).

The broker's maximum leverage is a ceiling, not a target. Use the stop distance to decide.
No stop, no trade: every order carries its stop, see Trade Gate.
Prop firms add their own limits (daily loss, max loss). Check them in the drawdown calculator.

Retail CFD leverage is limited by regulators in some countries. In Australia, ASIC's CFD product intervention order limits the leverage available to retail clients (ASIC consultation CS 64, October 2026; read ASIC's page for the current limits). VERIFY CURRENT DATA with the regulator and your broker.

Frequently asked questions

How is the lot size calculated?

Risk amount = daily starting equity x risk %. Stop distance = the absolute difference between entry and stop loss. Lots = risk amount / (stop distance x multiplier), rounded down to 0.01 so the loss at the stop never exceeds the amount you chose.

Which multipliers does it use?

Gold (XAUUSD) 100, WTI crude oil 1,000, EURUSD and GBPUSD 100,000, in units per 1.00 lot. Brokers differ, for example some use 100 barrels for oil, so check your broker's contract specification and use Custom if it is not the same.

Where do the 30% and 60% thresholds come from?

They are Marlin's own planning thresholds for how much of the day's remaining loss allowance one stop-out would use. They are not rules of any prop firm, and they are not a recommendation of how much to risk.

Are the presets the firms' real rules?

The limits come from the same published-rules data as our comparison page, read from each firm's own pages (VERIFY CURRENT DATA). They are the 2-step limits of 5% daily and 10% overall. Other programmes differ: FTMO's 1-Step has a 3% daily limit and a trailing maximum loss. Use Custom Account for them, and read the firm's page before you trade.

Why do I enter the daily starting equity?

Firms measure the daily loss from where the day started, not from today's balance. Enter the equity at the start of the trading day. If you already lost money today, enter it in the optional field: it lowers the allowance left.

Does it include spread, slippage and commission?

No. Real losses can be larger than the figure shown because of the spread, slippage, gaps over the stop, commissions and swaps. Treat the result as a planning figure.

What risk per trade should I use?

There is no correct number, and this page does not recommend one. The slider covers 0.25% to 2% and shows what each choice does to your daily allowance.

Embed this calculator on your site

Free to use. Use ?theme=light or ?theme=dark and ?defaultFirm=fundingpips or ftmo on the address, or build the code with the Embed Widget button above the calculator. The embed has no ads, no affiliate links, no cookies, and it does not save anything in the visitor's browser. Please keep the credit line. The script resizes the frame to fit the content and only accepts messages from the frame itself.

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<p style="font-size:11px;color:#71717a;max-width:600px">Prop firm calculator by <a href="https://marlinfx.com/trading-tools/prop-firm-lot-size-calculator/">Marlin</a></p>

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Written by

Volodymyr Kravchenko

Founder · Market Research

Independent market researcher focused on Forex, Gold, commodities, macroeconomic data and AI-powered financial intelligence.

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Educational research, not personal advice. See our editorial policy and methodology.

This content is provided for educational purposes only and is not investment advice. Trading involves risk, and past performance does not guarantee future results. Affiliate relationships may exist. Always conduct your own independent research before making financial decisions.