Margin Loan Calculator

About the Margin Loan Calculator

Margin loans let you borrow against the securities in your brokerage account to buy more investments or access cash. While leverage can amplify returns, it also amplifies losses — and if your portfolio drops below the maintenance margin, you face a margin call that can force the sale of your investments at the worst possible time.

The Margin Loan Calculator helps you understand the full cost and risk of margin borrowing. Enter your investment amount, margin loan size, interest rate, and holding period to see total interest costs. It also calculates the exact stock price that triggers a margin call based on your maintenance margin requirement.

Before borrowing on margin, you should understand both the interest expense and the liquidation risk. This calculator quantifies both so you can make an informed decision. Margin loans can amplify returns in a rising market, but they also magnify losses and carry the risk of forced liquidation at the worst possible time.

When This Page Helps

Brokerage firms make margin loans easy to access — often just a click. But the costs and risks are not always transparent. This calculator reveals the annual interest cost (which compounds and reduces returns), the margin call trigger price (the stock price that forces liquidation), and the effective break-even return your investment must achieve just to cover the borrowing cost.

How to Use the Inputs

1. Enter the total investment value (your equity + borrowed amount).
2. Enter the amount you are borrowing on margin.
3. Enter the margin interest rate (check your broker's rate schedule).
4. Enter the holding period in months.
5. Enter the maintenance margin requirement (typically 25-30%).
6. Review interest cost, margin call trigger, and break-even return.

Example Calculation

Tips & Best Practices

• Margin interest rates vary by balance tier — larger loans get lower rates (often 5-8% vs 8-12% for small balances).
• Interest is charged daily and debited monthly — it compounds if not paid from outside cash.
• Keep your equity well above the maintenance margin to avoid forced liquidation during market dips.
• Margin calls must be met quickly (usually 2-5 days) — you may be forced to sell at a loss.
• Margin interest is tax-deductible against investment income (not ordinary income) — consult a tax advisor.
• Consider margin as a short-term tool, not a permanent leverage strategy — interest erodes returns over time.

How Margin Leverage Works

With 50% initial margin, $50,000 of equity lets you buy $100,000 of stock. If the stock rises 20%, your portfolio is worth $120,000 and your equity is $70,000 — a 40% return on your equity. But if the stock drops 20%, your portfolio is $80,000 and your equity is $30,000 — a 40% loss on equity, plus interest.

The Margin Call Danger Zone

Brokers require maintenance margin (typically 25-30%) at all times. If a 30% market decline drops your $100,000 portfolio to $70,000, your equity is $20,000 (28.6% of portfolio). At 30% maintenance, you would get a margin call. Forced selling during a downturn locks in losses that might have been temporary.

Interest Eats Returns

At 8.5% margin rate, borrowing $50,000 costs $4,250/year. Your leveraged investment must return at least 4.25% (on the full $100,000) just to break even after interest. In a flat or modestly positive market, margin interest turns a small gain into a net loss.

When Margin Makes Sense

Margin can be rational for very short holding periods (days to weeks), as a bridge while waiting for fund transfers, or for tax-loss harvesting where you need to maintain market exposure. Using margin as permanent leverage is generally inadvisable for individual investors.

Frequently Asked Questions

• What is a margin call?

  A margin call occurs when your account equity drops below the maintenance margin requirement (typically 25-30% of the portfolio value). Your broker will demand you deposit more cash or securities, or they will sell your holdings to restore the margin. Some brokers liquidate automatically without notice.

• How is margin interest calculated?

  Margin interest is calculated daily on the outstanding loan balance using the broker's margin rate. It is typically charged monthly. The rate is usually variable and tied to the broker call rate or federal funds rate plus a spread. Rates range from 5% to 12%+ depending on the broker and loan size.

• Can I lose more than my initial investment?

  Yes. If your portfolio drops significantly and is liquidated at a loss, you still owe the full margin loan amount plus accrued interest. In extreme cases (rapid market decline), you can owe more than your original equity. This is the fundamental risk of leverage.

• What is the initial margin requirement?

  Regulation T sets the initial margin requirement at 50% for most stocks, meaning you can borrow up to 50% of the purchase price. Some brokers and specific securities may require higher initial margins. After purchase, the maintenance margin (typically 25-30%) applies.

• Is margin interest tax deductible?

  Margin interest is deductible as investment interest expense, but only against net investment income (dividends, interest, short-term capital gains). You cannot deduct it against salary or long-term capital gains without special elections. Carry unused deductions forward to future years.

• Should I use margin to invest?

  Margin can be appropriate for experienced investors with a high risk tolerance and a short time horizon for the leveraged position. It is generally unsuitable for long-term holding, retirement accounts, or investors who cannot tolerate forced liquidation during market downturns. The interest cost must be weighed against expected returns.