Open this calculator on its own page
🏦 Margin Call Price Calculator
Your stop is your decision. A maintenance call is your broker's. This is the price at which they stop asking.
💡 Quick Insight
Your loan does not shrink when the position falls, only your equity does. That is the whole reason the call price exists, and why it moves toward you rather than away from you. The percentage fall shown here applies to the share price too, as long as the loan is secured against a single position.
The Price Your Broker Starts Selling At
When you buy on margin you put up part of the value and borrow the rest. After that you must keep your equity above a maintenance requirement. The price at which you fail that test is not a matter of opinion. It falls out of three numbers you already have.
⚠️ The Formula
loan = position value − your equity
call value = loan / (1 − maintenance requirement)
fall to call = 1 − call value / position value
Worked once, slowly: you buy $20,000 of stock with $10,000 of your own money. Your loan is $10,000. At a 30% requirement the position can fall to $10,000 ÷ 0.70 = $14,286 before you fail. That is a 28.6% fall.
The Whole Lesson In One Grid
| Your equity | Leverage | Fall to a call at 25% | at 30% | at 35% |
|---|---|---|---|---|
| 100% (cash) | 1.00x | never | never | never |
| 75% | 1.33x | 66.7% | 64.3% | 61.5% |
| 60% | 1.67x | 46.7% | 42.9% | 38.5% |
| 50% (the Reg T maximum) | 2.00x | 33.3% | 28.6% | 23.1% |
| 40% | 2.50x | 20.0% | 14.3% | 7.7% |
| 35% | 2.86x | 13.3% | 7.1% | 0.0% |
| 33% | 3.00x | 11.1% | 4.8% | already breached |
⚠️ Read The Bottom Two Rows
At 2.86 times leverage against a 30% house requirement, a 7.1% fall brings the call. That is an ordinary week.
And the bottom-right cell is not a rounding artefact: at three times leverage against a 35% requirement you are below the threshold the moment you open, which is why a broker with a 35% requirement will simply refuse the trade.
What The Table Does Not Contain
Your entry. Your thesis. Your stop. The call price is a property of your borrowing, not of your idea, which is why it is the one number on this page you can compute before you have decided what to buy.
Common Margin Mistakes
Believing Your Stop Protects You
A stop is an instruction to trade at a price. A maintenance call is an instruction to you, and if it goes unmet the liquidation is the broker's, on their timetable, in whichever position is easiest to sell.
Problem: In a gap the stop and the call arrive together, and the stop is the slower of the two.
Using The 25% Regulatory Floor
25% is the minimum a broker is permitted to require, not the number in your agreement. House requirements of 30-40% are ordinary, and they are set higher still on volatile or concentrated names, sometimes after you have already opened the position.
Forgetting That The Loan Is Fixed
"I'm down 15%, so I have 15% less cushion." No. The loan does not move. A 15% fall takes 15% off the position and 30% off the equity at 2x leverage, which is why the distance to a call shrinks roughly twice as fast as the price does.
Meeting The Call By Selling At The Bottom
A call met by liquidation is met at the worst price of the drawdown, in the position with the best bid rather than the worst thesis. That is the broker optimising their exposure, not yours.
Professional Margin Discipline
Compute It Before You Open
The call price needs no entry, no target and no view. Decide the leverage first, read the fall to a call, and only then decide whether the trade is worth taking at that size.
Compare It To The Instrument's Actual History
A 28.6% cushion sounds generous until you check how often the thing you are holding has fallen 28.6% inside a month. Take the worst drawdown of the last two years and put it next to the number this calculator gives you.
Assume The Requirement Can Rise
Brokers raise house requirements on volatile names, and they do it in exactly the conditions that move you toward a call. Run the calculator a second time at a requirement five points higher than your agreement states, and treat that as the real number.
Concentration Is Leverage's Multiplier
The formula above treats the position as one thing. If your margin loan is secured against a portfolio, a call fires on the portfolio's equity. And the broker will sell whatever is most liquid, which is usually the position you least wanted to lose. Correlated holdings behave as a single position for this purpose.
📚 Learn More About Broker Mechanics
When Your Broker Acts Without You
Margin calls, assignment and pin risk, the three ways your position changes without your consent
Where the Stop Goes
Why a stop is an instruction to trade, not a guarantee of a price
Position Sizing
The multiplier in front of your risk, and how to choose it