Margin & Leverage Risk Calculator
Margin assumptions
Leverage and maintenance cushion
Current equity is 50% of the modeled holdings value. Before financing cost, maintenance excess equals 40% of current account equity.
Common-shock stress table
Each row applies the same percentage move to the full entered long holdings value, keeps the borrowed debit outstanding, adds the entered simple financing cost, and recalculates equity and maintenance excess. Real portfolios rarely move as one asset, so this is a leverage stress test rather than a security-by-security margin model.
| Holdings move | Holdings value | Equity after interest | Equity return | Maintenance excess | Cash to restore | Status |
|---|---|---|---|---|---|---|
| +10% | $220,000 | $119,178 | +19.18% | +$53,178 | $0 | Above entered requirement |
| 0% | $200,000 | $99,178 | -0.82% | +$39,178 | $0 | Above entered requirement |
| -10% | $180,000 | $79,178 | -20.82% | +$25,178 | $0 | Above entered requirement |
| -20% | $160,000 | $59,178 | -40.82% | +$11,178 | $0 | Above entered requirement |
| -27.98% | $144,031 | $43,209 | -56.79% | +$0 | $0 | Above entered requirement |
| -30% | $140,000 | $39,178 | -60.82% | -$2,822 | $2,822 | At / below entered requirement |
| -40% | $120,000 | $19,178 | -80.82% | -$16,822 | $16,822 | At / below entered requirement |
| -50% | $100,000 | -$822 | -100.82% | -$30,822 | $30,822 | At / below entered requirement |
| -75% | $50,000 | -$50,822 | -150.82% | -$65,822 | $65,822 | At / below entered requirement |
| -100% | $0 | -$100,822 | -200.82% | -$100,822 | $100,822 | At / below entered requirement |
How the maintenance threshold is calculated
In this simplified long-margin model, account equity equals holdings value minus the outstanding debit. The modeled maintenance threshold is the holdings value where that equity equals the reader-entered maintenance percentage of holdings value.
Gross leverage = holdings value ÷ account equity
Maintenance excess = account equity - holdings value × maintenance %
Maintenance threshold value = borrowed debit ÷ (1 - maintenance %)
Simple financing cost = debit × annual rate × days ÷ 365
With the default $200,000 of holdings and $100,000 of equity, the modeled debit is $100,000 and gross leverage is 2x. At a 30% entered maintenance requirement, the no-interest threshold is about $142,857, or roughly a 28.6% decline in holdings value from the starting level.
Where this calculator stops
This is not a brokerage margin calculator and does not estimate buying power, Regulation T initial margin, portfolio-margin offsets, security-specific haircuts, short-sale requirements, option margin, concentration charges, intraday rules, or liquidation priority. It also does not model deposits, withdrawals, dividends, taxes, commissions, changing interest rates, or different price moves across holdings.
Brokerage firms can impose house requirements above regulatory minimums, can change those requirements, and may liquidate positions without waiting for a customer to meet a margin call. Use the maintenance requirement shown by your broker when you want this page to approximate your current account rather than a hypothetical stress case.
For stop-based sizing before entering a stock position, use the Stock Position Size Calculator. For a beta-adjusted futures hedge estimate, use the Portfolio Hedge Calculator.
Margin-risk references
- FINRA: Know What Triggers a Margin Call, including maintenance equity, house requirements, and liquidation risk.
- Investor.gov: Understanding Margin Accounts, including the relationship between securities value, borrowed amounts, account equity, and maintenance requirements.