Margin Call Calculator
Estimate a long stock position's price threshold from your own initial and maintenance margin assumptions.
How it works
Enter purchase price per share, share count, initial margin percentage, and maintenance margin percentage. The two percentages are your scenario inputs, not rates supplied by the calculator.
The model calculates the initial loan as purchase value minus initial equity. It then solves for the price where equity divided by position market value equals the maintenance percentage. The loan remains fixed while the share price changes.
Results show the modeled threshold price, percentage drop from entry, equity at that threshold, and decrease in the position's market value. The worked example uses $100 per share, 100 shares, 50% initial margin, and 25% maintenance margin.
Change the margin assumptions to compare scenarios. Actual broker requirements and liquidation actions can differ, change over time, or apply to the whole account.
Step by step
- Enter purchase price, shares, and both margin percentages.
- Review the modeled threshold, drop, equity, and position price loss.
- Compare a different set of user supplied margin percentages.
Worked example
For 100 shares bought at $100, with 50% initial margin and 25% maintenance margin, the modeled threshold is $66.67 per share, a 33.33% drop from entry.
At that price, modeled account equity is $1,666.67 and the position has lost $3,333.33 in market value. The $5,000 initial equity is not a loss limit. Values are rounded to cents.
When to use this calculator
Use this calculator to see how supplied initial and maintenance margin percentages affect a simplified long stock threshold scenario.
Check your broker's current requirements and agreement for actual account thresholds and liquidation terms. This model does not predict broker action.
Common interpretation errors
Do not treat the modeled threshold as a guaranteed broker call price. Broker requirements can differ from your inputs and can change.
Do not interpret the position price loss as a cap on account losses. A gap or liquidation below the threshold can produce a larger loss, including a remaining loan balance.
Model calculation
initialLoan = shares × purchasePrice × (1 − initialMarginPct ÷ 100)
thresholdPrice = purchasePrice × (1 − initialMarginPct ÷ 100) ÷ (1 − maintenanceMarginPct ÷ 100)
thresholdEquity = shares × thresholdPrice − initialLoan
priceLossAtThreshold = shares × (purchasePrice − thresholdPrice)
The threshold solves shares × price − loan = (maintenanceMarginPct ÷ 100) × shares × price. The loan stays fixed in this model. Price loss is the change in position market value from entry to the modeled threshold, not a maximum loss.
Assumptions and limitations
The model covers one long stock position with a fixed loan and user supplied margin percentages. It does not model interest, fees, other holdings, short positions, options, portfolio margin, changing loan balances, broker specific requirements, or trading execution. Brokers may change house requirements and may liquidate securities without notice. A market gap can move the price past the modeled threshold. The threshold is not a maximum loss or a guaranteed broker call price.
Key terms
- Maintenance margin
- The equity percentage a broker or account agreement requires to remain in a margin account. The value varies by firm, security, and account.
- Initial margin
- The portion of a position's purchase value supplied as equity when opening the position. This calculator treats it as a user entered assumption.
- Modeled threshold price
- A simplified price for which position equity equals the supplied maintenance percentage of current position value, assuming a fixed loan and one long stock holding.
Related calculators
Estimate borrowing costs with Margin Interest Calculator, size an entry with Position Size Calculator, and compare a separate property loan scenario with Property Equity Price Drop Calculator.
Trailing Stop Loss Calculator shows stop price levels. A stop order does not guarantee an exit at that price, and this threshold model does not automate trades.
FAQ
What does the calculated threshold mean?
This simplified model starts with one long stock position and a fixed loan. It finds the price where account equity, calculated as position value minus the loan, equals the user entered maintenance percentage of position value. It does not predict when a broker will issue a call or sell securities.
How do initial and maintenance margin differ?
Initial margin is the share of the purchase value supplied as equity at entry. The remaining amount is the modeled loan. Maintenance margin is the user supplied equity percentage used to calculate the threshold. The calculator does not set these rates or identify a regulatory minimum.
Does this predict the margin call level at my broker?
No. The result applies only to the entered long stock position, fixed loan balance, and supplied margin percentages. Brokers can set different house requirements, change them, or calculate account requirements across multiple holdings.
Is the price loss at threshold a maximum loss?
No. The price loss at the modeled threshold is the decrease in the position's market value from entry to that price, not a maximum account loss. Prices can gap below a threshold, and a broker may liquidate without notice. For US accounts, FINRA's margin disclosure warns that firms can sell securities without contacting customers.
Which related calculators answer different questions?
Margin Interest Calculator estimates borrowing costs for a loan amount and rate. Position Size Calculator works from a risk budget and exit price. Trailing Stop Loss Calculator estimates stop levels, while Property Equity Price Drop Calculator models a separate property loan scenario.
Related calculators
Use Margin Interest Calculator for loan costs, Position Size Calculator for share count from a risk budget, Trailing Stop Loss Calculator for stop levels, and Property Equity Price Drop Calculator for a separate property loan scenario.