How to Use the Margin Call Price Calculator
Buying stock on margin means part of your position is funded by a loan from your broker, and if the stock falls far enough, the broker can force a margin call — or liquidate your position outright — to protect that loan. This calculator uses the standard Reg T framework: enter your purchase price, the initial margin (the share you funded with your own cash, typically at least 50% under Reg T), and your broker's maintenance margin requirement (FINRA sets a 25% minimum, though many brokers require more).
The math is straightforward: the larger the loan portion of your position and the higher your broker's maintenance requirement, the closer the margin call price sits to your original purchase price, leaving you less room before trouble starts. Funding more of the position with your own cash — a higher initial margin — pushes that trigger price lower and gives you more cushion against a downturn.
Keep in mind that actual maintenance requirements, house rules, and how quickly a broker liquidates positions after a call vary firm by firm and can be higher for volatile or concentrated stocks. Treat this result as a planning estimate, not a guarantee, and confirm your account's exact terms with your broker.
Frequently Asked Questions
Not always instantly. You'll typically get a margin call demanding more cash or securities, and if you don't meet it in time, the broker can liquidate positions without further notice — often at whatever price is available.
No. FINRA sets a 25% minimum, but many brokers require 30-40% or more, especially for volatile or concentrated positions. Always check your own broker's margin agreement.