Stock maintenance margin tool
Margin Call Calculator
Estimate current account equity, equity percentage, maintenance requirement, margin call price and cash required for a long or short stock position.
Margin account result
| Stock price | Position value | Account equity | Equity % | Status |
|---|
Margin call formulas
For a long position, the broker loan is the original purchase cost minus the investor’s cash contribution. Current equity is current market value minus that fixed loan. A margin call is indicated when current equity divided by current market value falls below the maintenance percentage.
Long equity = current price × shares − margin loan
Long call price = margin loan ÷ [shares × (1 − maintenance margin)]
Short equity = initial cash + short-sale proceeds − current price × shares
Short call price = (initial cash + short-sale proceeds) ÷ [shares × (1 + maintenance margin)]
Cash required = max(maintenance margin × current position value − current equity, 0)
The call-price formula identifies the price where equity percentage equals the entered maintenance requirement. A broker may act earlier, change the requirement without notice or liquidate without issuing a conventional call.
Verified examples
Long stock above maintenance
Suppose 100 shares are purchased at US$50 with US$2,500 cash and a US$2,500 margin loan. At US$40, market value is US$4,000 and equity is US$1,500, so equity percentage is 37,50%. With a 25% maintenance requirement, required equity is US$1,000 and no cash is required. The estimated call price is US$33,333333 per share. Unrealized loss is US$1,000, or −40% of the initial cash.
Long stock below maintenance
With the same position at US$30, market value is US$3,000 and equity is US$500, or 16,6667%. Required equity is US$750, so the simplified cash amount needed to restore 25% maintenance is US$250.
Short stock margin call
Assume 100 shares are sold short at US$50 with a US$2,500 initial margin deposit. At US$60, the short liability is US$6,000 and account equity is US$1,500, or 25%. With 30% maintenance, required equity is US$1,800 and the cash shortfall is US$300. The estimated call price is US$57,692308; unrealized loss is US$1,000.
Long and short margin accounts
| Item | Long stock | Short stock |
|---|---|---|
| Adverse price move | Price falls | Price rises |
| Broker balance modeled | Fixed margin loan | Short-sale proceeds held with initial cash |
| Call threshold | Price at or below the estimate | Price at or above the estimate |
| Maximum theoretical loss | Limited by a fall to zero, though equity can become negative | Unlimited as the stock price rises |
Limits and assumptions
- Prices must be positive and support up to eight decimal places. Shares must be a whole number from 1 to 10,000,000.
- Initial cash must be positive. For a long position it cannot exceed the original purchase cost; otherwise there is no margin loan.
- Maintenance margin must be greater than 0% and less than 100%.
- The cash-required result assumes cash is added to equity or applied against the financing balance without changing the stock quantity.
- Interest, commissions, borrow fees, dividends, taxes, settlement, accrued charges and previous withdrawals or deposits are excluded.
- Portfolio offsets, options, futures, crypto liquidation, tiered house requirements and portfolio-margin models are outside this single-stock calculator.
- A zero or negative equity result is displayed, but actual liquidation may have occurred earlier.
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