Margin Call Calculator for Account Equity Monitoring
Calculate current account margin, minimum maintenance equity, and excess or shortfall from account equity, market value, and maintenance percentage.
Enter account equity, securities market value, and maintenance margin to see current margin, required equity, and excess or shortfall.
About margin calls and maintenance equity
A margin call calculator compares the equity in a brokerage margin account with the maintenance cushion a firm requires. Current margin is account equity divided by the market value of the securities, expressed as a percent. Minimum equity is market value times the maintenance rate. Excess or shortfall is equity minus that minimum. A positive excess means a buffer. A negative shortfall is the cash or liquidation gap implied by the rate you entered. On $30,000 of equity and $100,000 of securities with a 25% maintenance rate, current margin is 30%, minimum equity is $25,000, and excess is $5,000. Drop equity to $20,000 on the same positions and current margin is 20%, which sits below 25%; the shortfall is −$5,000. When equity exactly equals the requirement, excess is $0.00 and the account is on the maintenance line. Regulation T and FINRA set baseline initial and maintenance margins in the United States, and brokers often impose higher “house” rates, especially on concentrated or volatile names. Overnight versus intraday rules, portfolio margin, and futures margins use different formulas. This estimate is a single-rate snapshot: it does not haircut individual positions, apply concentration add-ons, or model a Fed initial-margin 50% purchase. Account equity should be the firm’s equity figure (long market value minus debit, plus credit, plus cash), not the gross long value. Market value should be the long securities you are measuring against that equity. If you include short positions, the broker’s margin engine is more involved than this ratio. A falling market reduces both equity and market value, but equity usually falls faster on a leveraged long, which is why calls appear in drawdowns. Use the margin call calculator to test a 25% maintenance case with a surplus, a shortfall, and an exactly-at-requirement run. Treat a negative excess as a warning to add cash or reduce size, then confirm house requirements, call deadlines, and liquidation rights with the broker agreement. This is an educational estimate, not a notice from your firm.
Current margin = account equity ÷ market value × 100; minimum equity = market value × (maintenance rate ÷ 100); excess or shortfall = equity − minimum equity.
Margin call calculation examples
These worked examples use the same current-margin, minimum-equity, and excess formulas as the margin call calculator.
| Input | Output | Note |
|---|---|---|
| $30,000 equity; $100,000 market value; 25% | $5,000.00 | Current margin is 30.00%, minimum equity is $25,000.00, and excess is $5,000.00 above a 25% maintenance line. |
| $20,000 equity; $100,000 market value; 25% | -$5,000.00 | Current margin is 20.00%, below the $25,000.00 requirement, so the shortfall displays as −$5,000.00. |
| $50,000 equity; $200,000 market value; 25% | $0.00 | Current margin is 25.00%, matching maintenance, so excess is $0.00 and the account sits on the requirement. |
How to check a margin call cushion
- Enter Account Equity as reported for the margin account, not the full market value of the longs.
- Enter Securities Market Value for the positions you are measuring.
- Enter Maintenance Margin (%) used by the broker, such as 25 for a common house rate.
- Select Calculate to see current margin, minimum equity, and excess or shortfall, then stress equity lower to test a drawdown.
Margin call calculator FAQ
What does a negative excess mean?
A negative excess or shortfall means account equity is below minimum equity at the maintenance rate you entered. In a live account that gap is the amount of cash or liquidation typically needed to restore the requirement, subject to the broker’s rules and timing.
Is 25% the official maintenance margin?
FINRA generally sets a 25% maintenance margin on long equity as a floor, but brokers often use a higher house rate. Enter the rate that applies to the account or strategy you are modeling rather than assuming 25% is always enough.
Does the margin call calculator use Regulation T initial margin?
No. It compares current equity with a maintenance percentage on market value. Initial margin on a new purchase, day-trading buying power, and portfolio-margin scenarios need the broker’s own formulas.
Should I enter cash as market value?
Usually no. Securities Market Value is the long (or measured) position value. Cash is already reflected in Account Equity. Putting cash into market value distorts current margin.
Can a margin call happen before excess reaches zero?
Yes. Intraday house calls, concentrated-position add-ons, and delayed equity calculations can trigger sooner than this snapshot. Use the estimate as a buffer check, then watch the broker’s live excess-maintenance figure.