Margin Call Calculator
Calculate at what price a margin call is triggered on a leveraged stock position.
What this calculator does
This calculator answers the question every leveraged trader should settle before opening a position: how far can this fall before I am closed out? The formula takes the purchase price, the proportion you funded yourself, and the maintenance level your provider enforces, and returns the price at which a call is triggered.
It turns two abstract percentages into one concrete number. Above that price nothing happens. At or below it, you face a demand for more funds, and if you cannot meet it quickly your positions are closed at whatever the market happens to be offering at that moment.
When to use it
Run it before you open the position rather than afterwards. Knowing the close-out price in advance lets you compare it against the instrument's normal volatility and against how much cash you could realistically transfer at short notice on a bad morning.
It also deserves a rerun whenever your provider changes its margin requirement, which happens on volatile instruments and around earnings or political events, and after any significant price move. A position that sat comfortably above its trigger last quarter may be uncomfortably close to it today.
Understanding the inputs
Purchase price is the price per share or per unit at which the leveraged exposure was opened. Initial margin is the percentage funded from your own money — under FCA rules, retail share CFDs require at least 20 percent, so leverage is capped at 5:1.
Maintenance margin is the minimum equity percentage the provider requires. Read your own terms rather than assuming a standard figure: requirements vary widely by instrument, and the FCA's close-out rule bites when equity reaches 50 percent of the initial margin requirement, which may arrive before the contractual maintenance level.
How is this calculated?
Margin Call Price = Purchase Price × (1 − Initial Margin) / (1 − Maintenance Margin).
A worked example
Suppose you open a position at £40 per share on 1,000 shares, a £40,000 exposure, funding £20,000 yourself and borrowing the rest. The provider's maintenance requirement is 25 percent. The trigger price is £40 times 0.50 divided by 0.75, which is £26.67.
That is a 33 percent fall — unremarkable for a single share over a bad quarter. At that price the position is worth £26,670 and your equity £6,670, exactly 25 percent. Under a stricter 30 percent requirement the trigger would rise to £28.57, meaning only a 29 percent fall is needed to force the issue.
Limitations and assumptions
Leveraged trading can lose you money rapidly, and outside retail accounts with negative balance protection your losses can exceed your deposit. Even with that protection, the entire account balance is at risk. Providers are required to disclose that a large majority of retail CFD accounts lose money, and they consistently do.
This calculation excludes overnight financing charges, dividend adjustments, spreads, and changes to margin requirements, any of which can bring a call forward. Past returns do not predict future ones and the model assumes no volatility. This is not investment advice and leverage is unsuitable for most investors.
Common Questions
- What is a margin call?
- A demand from your broker or CFD provider for more funds because the equity supporting your position has fallen below the maintenance level. You typically have a short window to meet it. If you do not, the provider closes your positions at whatever price is available, not one you choose.
- At what price is a margin call triggered?
- Purchase price times one minus initial margin, divided by one minus maintenance margin. Buying at £40 having funded 50 percent yourself, with a 25 percent maintenance requirement, gives a trigger at £26.67 — a fall of a third. With a stricter 30 percent requirement, the trigger rises to £28.57.
- What are the FCA rules on leverage?
- The FCA caps leverage for retail clients on CFDs and spread bets by instrument — 5:1 on individual shares, 20:1 on major indices, and 2:1 on cryptocurrency. It also mandates negative balance protection and automatic close-out once account equity falls to 50 percent of the required margin.
- What is negative balance protection?
- An FCA requirement that a retail client's losses on CFDs and spread bets cannot exceed the funds in the account. It means a retail trader cannot end up owing the provider money after a gap. It applies to retail categorisation only — elective professional clients give this protection up.
- Can I still lose more than I put in?
- On a retail CFD or spread betting account with negative balance protection, no — losses stop at your account balance, which you can still lose entirely. On a margin loan from a stockbroker, or as an elective professional client, yes, you can end up owing more than you deposited.
- Does the provider have to warn me before closing positions?
- Not meaningfully. Providers typically send an automated notification, but the contractual right to close positions without notice is standard, and the FCA close-out rule requires them to act when margin falls to 50 percent of the requirement. Relying on a warning arriving in time is not a strategy.
- How do financing costs affect a leveraged position?
- Substantially. CFD positions held overnight incur a daily financing charge, commonly a spread over the benchmark rate, applied to the full position value. At 7 percent on a £40,000 position that is roughly £2,800 a year the trade must earn before you break even — a drag the trigger price ignores.
- How is spread betting taxed?
- Profits from spread betting are generally free of capital gains tax and stamp duty for UK individuals, because it is treated as a bet rather than an investment. The corollary is that losses cannot be offset against gains elsewhere. CFDs are subject to CGT but also escape stamp duty reserve tax.
- How do I monitor my equity percentage?
- Divide equity by the total market value of your positions. Holding £100,000 of exposure against £40,000 borrowed leaves £60,000 of equity, or 60 percent. Track that ratio rather than the share price, because it is the ratio that determines whether a call arrives, and it moves faster than the price does.
- Is leverage ever sensible for a retail investor?
- Rarely, and the regulator's own data is blunt about it — providers must publish the percentage of retail accounts losing money on CFDs, and the figures have consistently sat between roughly 70 and 80 percent. Leverage magnifies a normal market drawdown into a forced, permanent loss.