Futures Position Size Calculator
Pick your contract, set your risk, and see how many contracts that actually allows. Tick sizes and tick values for the CME contracts are already in.
E-mini S&P 500 — 0.25 tick worth $12.50, so $50 a point.
Risking $500 on this trade.
20 ticks away.
Position Size
2contracts
Exact size 2, rounded down
Maximum Risk
$500
1% of the account
Risk Per Contract
$250
20 ticks × $12.50
Potential Loss
-$500
If the stop is hit as planned
Risk / Reward
1 : 3
Break even winning 25% of the time
- This position is worth about 1000% of your account. Your loss is still capped at the risk you set, but funding it needs margin or leverage.
Why futures maths is genuinely different
In stocks, a one dollar move on one share is one dollar. In futures it is not: each contract has a tick size set by the exchange and a fixed amount of money attached to that tick. An E-mini S&P contract moves in quarter-point ticks worth $12.50 each, so a ten-point stop is forty ticks and $500 of risk on a single contract.
Getting this wrong is expensive in a specific way. Sizing an ES trade as though a point were a dollar understates your risk by a factor of fifty, and the mistake only becomes visible when the stop is hit.
Ticks, points and contract value
Tick value divided by tick size gives the point value: $12.50 over 0.25 is $50 a point for ES. This page derives it rather than storing it separately, so the two can never disagree.
Micro contracts are exactly one tenth of their full-size sibling. MES is $1.25 a tick against ES at $12.50, which is what makes them the practical choice for an account too small to risk a full contract on a sensible stop.
When one contract is already too much
Futures cannot be traded fractionally. If the arithmetic says 0.4 contracts, the honest reading is that this trade at this stop distance does not fit your account — not that you should round up to one.
The two real options are a smaller contract, if a micro version exists, or a tighter stop that you would have placed anyway for reasons other than making the size work. Widening your risk percent to justify the position is how accounts get into trouble.
Common questions
- How many futures contracts should I trade?
- Divide the money you are risking by the risk on one contract, which is your stop in ticks multiplied by the tick value. Round down: a partial contract cannot be traded.
- What is the tick value of ES?
- The E-mini S&P 500 moves in ticks of 0.25 index points, each worth $12.50, which works out to $50 per full point. The micro version, MES, is $1.25 a tick and $5 a point.
- Why does the calculator say I can only trade 0.4 contracts?
- Because at that stop distance a single contract would risk more than the percent you set. Use a micro contract if one exists for that market, or accept that the trade does not fit the account — do not round up.
- Does this include margin?
- No, and the two are separate questions. Margin is what the broker requires you to post to hold the position; risk is what you lose if the stop is hit. A position can be well within your margin and still be far too large for your account.
Sizing a different market
This website provides educational information only. It is not financial, investment, or trading advice. Results assume your stop fills at the stop price; gaps, slippage, spread and commissions are not included and will change your real outcome.