Futures Position Size Calculator
Work out how many futures contracts to trade so a stop-out costs a fixed percentage of your account.
This futures position size calculator answers how many contracts to trade with exact arithmetic: the stop distance in points multiplied by the contract's point value gives the cash risked per contract, and the risk budget divided by that gives the count.
Formula: contracts = floor((balance x risk%) / (stop in points x point value))
Your figures
Sets the point value and tick size. Choose 'Custom' to enter them yourself.
Distance from entry to stop, in points.
Contract currency to your account currency. 1 when they match. Use the rate that applied on the day for a past trade.
Only used when Contract is set to Custom.
Only used when Contract is set to Custom.
Results
Position size
1 contract
32-tick stop on ES — E-mini S&P 500
- Risk budget
- US$500.00
- Risk per contract32.0 ticks at US$12.50 each.
- US$400.00
- Exact size before rounding
- 1.250
- Actual risk at this size
- US$400.00
- Actual risk as a percentage
- 0.800%
What this means
1 contracts risks US$400.00 against a US$500.00 budget. Futures trade in whole contracts, so the size is rounded down — rounding up would risk more than intended, and on small accounts that rounding step is coarse.
- Rounds down, so the position always risks the same as or less than the budget.
- Excludes commission and exchange fees, which add to the cost of a losing trade.
- Assumes the stop fills at its price. Futures gap between sessions and around economic releases.
Position size: 1 contract
The link reopens this calculator with the same numbers. Nothing you enter is sent to a server.
Continue with these figures
About the Futures Position Size calculation
What makes it different from other instruments is that the answer must be a whole number. Futures cannot be traded fractionally, so the calculation is followed by rounding down — and on a smaller account that rounding is coarse.
The step between one contract and two is a 100% change in position size, and an ES position size cannot sit anywhere between them. Between four and five it is 25%. That granularity is the main practical constraint on smaller futures accounts, and it is the reason the micro contracts exist.
Futures Position Size formula
risk budget = balance × risk % ÷ 100
risk per contract = stop in points × point value
contracts = floor(risk budget ÷ risk per contract)
actual risk = contracts × risk per contract- floor
- Round down. Rounding up would risk more than the budget allows.
- risk per contract
- Cash lost on one contract if the stop is hit.
- stop in points
- Distance from entry to stop, in the contract's quoted points.
Rounding down means the position almost always risks less than the budget, sometimes considerably less. A budget of $500 against $400 per contract funds one contract and leaves $100 unused — the exact figure was 1.25, and there is no way to trade the remaining quarter.
This is where micro contracts earn their place. A full-size E-mini at a 20-point stop risks $1,000, so a $100 budget funds none at all; the micro version risks $100 and funds exactly one. The same account can size properly on the micro and cannot participate at all in the full-size contract.
The relationship between stop distance and size is the same inverse one as in every other market: halving the stop doubles the contracts the budget funds. What differs is that the result then has to survive rounding, which can undo the change entirely on a small account.
Futures Position Size: a worked example
A $50,000 account risking 1% per trade on the E-mini S&P 500 (ES), with an 8-point stop.
- Risk budget50,000 × 1% = $500
- Risk per contract8 × $50 = $400
- Exact size500 ÷ 400 = 1.25 contracts
- Rounded down1 contract
- Actual risk$400 — 0.8% of the account
- Stop in ticks8 ÷ 0.25 = 32 ticks
One contract, risking $400 rather than the $500 budgeted. Trading the micro version instead would allow 12 contracts and land far closer to the intended risk.
How to use the Futures Position Size calculator
- Choose the contract so the point value is set from its specification.
- Enter your account balance and the percentage you are willing to risk.
- Enter the stop distance in points, not ticks. The calculator converts to ticks for reference.
- Check the actual risk after rounding — it is usually below the budget, sometimes well below.
- If the result is zero contracts, look at the micro version of the same contract.
Limitations of the Futures Position Size calculator
Every calculation makes assumptions. These are the ones that matter here.
- Rounds down always, so the realised risk is at or below the budget rather than at it.
- Excludes commission and exchange fees, which add to the cost of a losing trade and are charged per contract.
- Assumes the stop fills at its price. Futures gap between sessions and around scheduled economic releases, where slippage can be substantial.
- Does not check whether the resulting position can be margined — use the margin calculator alongside it.
Frequently asked questions about Futures Position Size
Why does the calculator round down rather than to the nearest contract?
Because rounding up breaches the risk limit you set. Going from 1.25 contracts to 2 would risk 160% of the budget. Rounding down can only reduce the risk taken.
The result is zero contracts. What are my options?
The risk budget does not cover a single contract at that stop distance, so a full-size ES position size is simply out of reach at that balance. A tighter stop, a higher risk percentage, a larger account, or the micro version of the contract — usually a tenth the size — are the four levers.
How does a micro futures position size compare?
A micro is usually a tenth of the full-size contract, so it lets smaller accounts size precisely rather than being forced into a position that is too large or none at all. This calculator does not recommend one over the other; it shows what each allows at your account size.
Does the margin requirement affect the position size?
It caps it. This is a futures risk calculator rather than a margin one: risk-based sizing tells you how many contracts your stop allows, while margin tells you how many your balance can support. The lower of the two is what you can actually trade, which is why the margin calculator is worth running alongside this one.
Last reviewed . See our methodology and editorial policy.
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