Tools
Futures Position Size Calculator
Work out how many contracts you can trade so that, if your stop is hit, you lose no more than you planned. It works for a personal account (risk a % of your balance) and for a prop firm account, where the number that matters is the distance to your drawdown floor and daily loss limit, not the headline account size.
Position size calculator
Specs from CME Group, checked 14 October 2026
- Contracts (rounded down)
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- Stop distance
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- Risk per contract
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- Risk budget
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- Limited by
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- Total risk at stop
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- Budget used
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- Same trade, micro/mini
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- Reward : risk
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- Reward at target (net)
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Always rounds down. Arithmetic on the numbers you enter. Not advice.
The formula
- Stop distance in ticks = |entry − stop| ÷ tick size
- Risk per contract = (stop ticks + slippage ticks) × tick value + round-trip fees per contract
- Risk budget = the smallest of: - account balance × risk % (or a fixed $ amount you choose) - distance to your drawdown floor − a safety buffer (prop accounts) - remaining daily loss limit (if your account has one)
- Contracts = round down (risk budget ÷ risk per contract), then cap at your firm's maximum position size
Always round down. Rounding up means a full stop-out loses more than your budget.
Example 1: personal account
$50,000 balance, 1% risk ($500). ES long at 6,000.00, stop 5,996.00 (4 points). - Stop = 4 ÷ 0.25 = 16 ticks - Risk per contract = 16 × $12.50 = $200 - Contracts = 500 ÷ 200 = 2.5 → 2 ES (actual risk $400)
On MES the same trade is $20 per contract, so the same $500 allows 25 MES.
Example 2: prop firm evaluation
50K evaluation, $1,500 left above the trailing floor, you keep a $300 buffer, and your personal per-trade cap is $200. MNQ long at 20,000, stop at 19,980 (20 points), round-trip fees about $1.04 per contract (enter your own). - Stop = 20 ÷ 0.25 = 80 ticks → 80 × $0.50 = $40.00 + $1.04 = $41.04 per contract - Budget = min($200, $1,500 − $300) = $200 - Contracts = 200 ÷ 41.04 = 4.87 → 4 MNQ
The same stop on full-size NQ is $400 per contract, which is over the $200 budget, so the answer is 0 NQ. The calculator says so plainly rather than rounding up to 1.
How much should you risk per trade?
There is no correct number, but the arithmetic is useful:
- Personal accounts: many risk-management guides use 0.5–2% of the account per trade. At 1%, ten losses in a row costs about 10%.
- Prop accounts: your "account" is effectively the drawdown, not the 50K/100K/150K label. A 50K account with a $2,000 maximum loss gives you $2,000 to work with. Risking $500 per trade means four straight losses end the account; risking $100–$200 means it takes 10–20.
- Count the daily limit. If the account has a $1,000 daily loss limit and you risk $250 a trade, four losers end your day.
Prop firm contract limits
Firms cap how many contracts you can hold, and some count micros against minis at 10:1. Two examples from the firms' own help pages (checked 14 October 2026):
- Topstep Trading Combine: 5 contracts / 50 micros on 50K, 10 / 100 on 100K, 15 / 150 on 150K; micros and minis count at 10:1. (Topstep)
- Apex Trader Funding evaluations: 4 max contracts on 25K, 6 on 50K, 8 on 100K, 12 on 150K. (Apex EOD evaluations)
The maximum is a ceiling, not a target. Your risk budget usually binds well before it does.
Questions people ask
How many contracts should I trade?
Divide the amount you are willing to lose on the trade by the dollar risk of one contract at your stop, and round down. If the answer is below 1, the trade is too big for your budget on that contract; consider the micro.
How do I calculate risk on a futures trade?
Stop distance in ticks × tick value × contracts, plus fees and any slippage you expect. A 10-tick stop on 2 ES is 10 × $12.50 × 2 = $250.
How many contracts can I trade on a Topstep 50K?
In the Trading Combine, up to 5 contracts or 50 micros at a time, per Topstep's help center. That is the cap; what you can afford to risk is usually lower.
How many contracts can I trade on an Apex 50K?
Apex lists a 6-contract maximum on its 50K evaluations (checked 14 Oct 2026). Check the current help center for funded (PA) limits and scaling.
Should I use micros or minis on an evaluation?
Micros let you size in finer steps. With a $200 budget and a 20-point NQ stop, NQ doesn't fit at all while MNQ allows 4 contracts. Many traders start on micros for that reason.
What is a good risk-reward ratio?
It depends on your win rate. At a 1:1 ratio you need to win more than half the time after costs; at 2:1, roughly a third. The calculator shows the ratio when you enter a target.
Sources
- Tick values: CME Group contract specifications (see tick value page) and AMP Futures spec table
- Topstep: Trading Combine Parameters (max position size, 10:1 micro ratio)
- Apex: EOD Evaluations (max contracts, DLL)
Set the size once per account, then trade as normal.
In Edgeable each follower gets its own multiplier, a max-contracts cap and a daily loss limit that stops copying to that account when it's reached. Set your sizing rules per account and trade your leader as usual. Runs in the cloud. See guardrails.
Guardrails are software controls, not guarantees; orders can still be delayed, rejected or filled differently across accounts. Not financial advice. Risk disclosure.