How this calculator works
A futures position is secured by margin, which is a performance bond rather than a down payment. The initial margin is the amount required to open the position. Each day the position is marked to market: gains are credited and losses are charged against the margin balance. If the equity falls below the maintenance margin, the broker issues a margin call and the holder must add cash, usually back up to the initial margin, or close the position. This calculator computes the current equity from the initial margin plus the position profit or loss, checks it against the maintenance requirement, and solves for the price that would use up the buffer between initial and maintenance margin.
Formula
Position profit or loss = (current - entry) x point value x contracts for a long, or (entry - current) x point value x contracts for a short. Equity = initial margin x contracts + profit or loss. Maintenance requirement = maintenance margin x contracts. A margin call occurs when equity < maintenance requirement. The margin call price is entry - (initial - maintenance) / (point value x contracts) for a long and entry + the same gap for a short.
Worked example
One long contract at 4,500 with a $50 point value, $12,000 of initial margin and $10,000 of maintenance margin falls to 4,450. The loss is 50 x $50 = $2,500, leaving equity of $9,500 against a $10,000 requirement, so a margin call of $500 is issued and $2,500 is needed to restore the initial margin. The margin call price is 4,500 - 2,000 / 50 = 4,460.
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Frequently asked questions
Why is the margin call price above the current price for a long position?
A long position loses as the price falls. The call price is the point where the remaining buffer between initial and maintenance margin is used up, so it sits below the entry price but above the current price once a call has been triggered.
Do brokers always require the full initial margin after a call?
Most require a top-up back to the initial margin, but practice varies. Some allow a partial reduction of the position instead, and the house rules set the deadlines.
Is margin the same as the money at risk?
No. The margin is a good-faith deposit. Losses can exceed the margin, and the holder remains liable for the shortfall, which is why futures can lose more than the amount initially posted.
Why does this use per-contract margins?
Exchange and broker margin requirements are quoted per contract. Multiply by the number of contracts to get the total requirement for the position.