Futures Position Size Calculator

How a budget turns into a contract count

People reach this from either word order — futures position size calculator, and position size calculator futures — and both arrive at the same one line of arithmetic. The money you accept losing, less the cost of getting in and out, divided by what one contract loses between your entry and your stop. Nothing in that sentence is specific to futures; what is specific is that the size comes back as a whole number of contracts.

1. The budget is the only number chosen without looking at price. It comes from the balance and the percentage decided in advance, and it is measured in your own currency.
2. The stop distance is measured in points, not in percent. A US30 stop fifty points below the entry is fifty points whether the index prints 40,000 or 20,000, and the spread is added because the exit crosses it just as the entry did.
3. The value per point per contract converts points into money. Every index row in the reference dataset publishes 1.00 per index point per unit of size; an exchange-traded contract publishes its own multiplier, and that figure belongs in the field above — it is not something this page can assume.
4. The division gives contracts, and rounding happens last, downwards. Contracts are integers on these rows, so a computed 1.8431 is sent as 1, and the unused 0.8431 of a contract is money that stays in the account rather than risk that creeps back in.

The last two lines of the formula are where futures differ most from forex. In forex the step is a thousand units out of a hundred thousand, so rounding is invisible. Here the step is the whole unit, and on the examples below it silently eats nearly half of a small budget.

Worked example: 1% of 10,000 against a 50-point stop on US30

Every price below is an input you type, not a quote — the page has no feed. US30 in the reference dataset quotes in USD with a pip size of 1, a contract size of 1 and a unit step of 1, so one unit of size gains or loses 1.00 for every index point the price moves.

1. Risk budget: 10,000.00 × 1% = 100.00 USD.
2. Stop distance: 40,000.00 − 39,950.00 = 50.00 points, which is 0.125% of the entry price.
3. Effective stop distance: 50.00 + 1.00 = 51.00 points.
4. Loss per contract: 51.00 × 1.00 = 51.00 USD for one contract held to the stop.
5. Budget left after commission: 100.00 − 6.00 = 94.00 USD.
6. Contracts: 94.00 ÷ 51.00 = 1.8431 contracts.
7. Round down to the step: floor to 1 contract, and 0.8431 of a contract — 43.00 USD of the budget — is never put at risk.
8. Check the worst case: 1 × 51.00 = 51.00, plus 6.00 commission = 57.00 USD. Inside the 100.00 budget with 43.00 to spare.
9. Check the notional: 1 × 1.00 × 40,000.00 = 40,000.00 USD, which is 400% of the account while the risk is 1%.

Step 8 is worth doing by hand even when the tool has already printed it: recompute the loss from the size you are actually sending. It is 57.00 here, not 100.00, and the difference is the contract count refused to carry.

Twelve index contracts, three identical numbers

Forex traders carry a mental table of contract sizes: 100,000 units to a lot, 100 ounces of gold, 1,000 barrels of WTI. Index contracts in this dataset do not need one. Below is every index row the site publishes, and the three columns that decide the money are the same on every single one.

Because the three columns are identical, the size a given budget buys on any of these twelve rows is the same number of contracts. What differs between them is the entry price, and therefore how much notional those contracts represent — which is the subject of the next table.

One contract is a lot of notional

The worked example above is the honest version of a small futures account: the size is one contract, and the notional is four times the equity. Below is the same 94.00 net budget put to work at six stop distances on the same 40,000.00 entry.

Two things in that table are worth reading twice. The notional column is three to thirty-two times the account while the risk stays at one hundred — that is not leverage in the sense of borrowing, it is simply what one index contract costs to hold. And the last row is not a rounding error waiting to be fixed: at a hundred-point stop this budget buys less than one contract, so the honest answer is that the trade cannot be sized, exactly as it would be printed by a small-account check.

The step is what binds

Rounding down to whole contracts strands part of the budget, and how much depends entirely on how big the account is. Here is the same 50-point stop, the same 1.00 per point and the same 6.00 commission, run across five balances at 1% risk.

The stranded share falls from 45.7% to 0.3% as the balance grows, because the same fixed cost per contract becomes a smaller fraction of a larger budget. Nothing about the edge changed — only the granularity. On small futures accounts that granularity is the binding constraint, not the risk percentage, and no amount of conviction recovers the 43.00.

This page and its neighbours, side by side

All four work from the same division, and they split the subject at the product line.

• This page counts whole contracts. Points of stop multiplied by what one point is worth, then floored to integers, with the notional that follows.
• The crypto futures page deals with the borrowed version: contract count on a perpetual, margin, funding payments and the liquidation price that can arrive before your stop. Read it when the instrument is crypto rather than an index.
• The page of contract specifications is where the three numbers behind this one come from — pip size, contract size and unit step for all 131 symbols in the dataset, including the three energies and four metals whose multipliers differ from these twelve rows.
• Margin is someone else's subject. How much the venue freezes, and how far price must travel before a call, belong to the margin calculator and the margin call calculator. Nothing here requires leverage: the size is derived from the stop, not from what the account could borrow.

If you arrived looking for a forex, gold or stock equivalent of the same arithmetic, the position size calculator on the home page runs the identical formula against every instrument in the dataset.

Questions traders ask

How do I calculate futures position size?

Divide the money you accept losing, after commission, by what one contract loses between your entry and your stop. On the example above: budget 100.00 less 6.00 commission is 94.00, the stop is 50.00 points plus 1.00 of spread = 51.00, and one contract loses 51.00 at 1.00 per point, so 94.00 ÷ 51.00 = 1.8431, floored to 1 contract. Recompute the loss from what you actually send — 1 × 51.00 + 6.00 = 57.00 — to confirm it sits inside the budget.

Why can I only trade one contract when the maths says 1.84?

Because the unit step on these index rows is one whole contract, and the size always rounds down. Sending 2 would risk 2 × 51.00 + 6.00 = 108.00 against a 100.00 budget, which is an 8% overshoot of the risk you chose. The unused 0.8431 of a contract strands 43.00 of the budget; it does not license rounding up.

Risk is 1%, so why is four times my account in the trade?

Because exposure and risk are different quantities. One US30 contract at a 40,000.00 entry is 40,000.00 of notional — 400% of a 10,000.00 account — while a 51.00-point move against it costs 51.00, because one point is worth 1.00 and the stop is only 0.125% of the price. Nothing is borrowed to make that true; it is simply what one contract is.

What do I type in "value per point per contract"?

The amount one unit of size gains or loses when the price moves one full point. Every index row in the site's dataset publishes 1.00, and that is the default here. An exchange-traded contract publishes its own figure — for example a multiplier quoted in dollars per index point — and that number belongs in this field, because nothing on this page can assume it for you.

The calculator returns zero contracts. What changed?

The computed size fell below one whole contract, so the page returned zero instead of rounding up. On the table above that happens between a 75-point and a 100-point stop: 94.00 ÷ 101.00 = 0.9307. The choices are a tighter stop, a larger risk percentage, a larger account, or an instrument whose step is smaller than one contract — not a size typed in by hand.

Do I have to convert anything on these index rows?

Only if your account is not in dollars. All twelve index rows quote in USD, so on a USD account the rate is 1 and nothing is converted. On another account currency you type the rate as units of your currency per one dollar, and the budget is converted once before the division; leave it blank and every figure stays in dollars, with a note saying so.

What the contract count does not cover

It is the size of one position, decided before the order goes in. Four things sit outside it on purpose.

• The exit. A stop is an instruction, not a guarantee. Index futures gap across the weekend and around the cash open, so the realised loss can exceed the distance the size was built on.
• Costs charged while you hold. Financing on a position carried overnight and the exchange and clearing fees billed separately are not entry costs, and they do not belong in the stop distance.
• Margin and liquidation. What the venue freezes, and where it closes you out, are decided by its own rules and are the subject of the margin and margin call pages rather than this one.
• Other positions already open. Four trades at 1% each are close to 4% of the account at once, and on index contracts that all trade the same session it is closer to one bet placed four times — which is what the account-level risk page adds up.

Everything on this page runs in your browser from the numbers you type and the twelve published specification rows above. The dataset behind it, with the same columns, is published as an open reference dataset.

Size the futures trade from your risk

Related guides

• Position sizing for crypto futures — contract count, funding and the liquidation price that sits behind your stop.
• Position size by instrument — contract size, pip size and unit step for all 131 symbols in the dataset.
• Position sizing on a small account — what to do when the minimum size is bigger than the risk allows.
• Forex margin calculator — what the venue freezes against these sizes, and how far price must travel before a call.
• Forex risk calculator — add the tickets already open and see what the account is actually carrying.
• Open reference dataset — the four CSV files behind every table on this page.