Margin & interest calculator

A free educational tool for understanding margin trading costs and break-even math. Enter your own numbers below — nothing is pre-filled with anyone's specific trades.

Educational tool — not investment advice. This calculator performs simple math on the numbers you enter. It does not predict returns, recommend any trade, or account for taxes, dividends, stop-loss execution, or price slippage. Margin trading involves substantial risk of loss including the loss of more than your initial deposit. See our Financial Disclaimer.

Your trade scenario

Dollars you personally fund. Broker lends the rest based on margin requirement.

30% means broker requires you put up 30% and lends the other 70%. Check your account; varies by stock and broker.

What your broker charges on the borrowed amount. Most brokers post this on their site.

Trading days you hold before selling. Interest is charged daily.

Most discount brokers charge $0–$10 per trade. Add your buy + sell total.

Used to show what +X% and -X% would do to your invested cash. Enter as a positive number.

What the math says

Enter your numbers on the left to see break-even prices, interest cost, and what gains and losses would look like.
Risks of trading on margin

Trading on margin amplifies both gains and losses. Understand each of these before borrowing from a broker to trade:

  • You can lose more than you invested. If a position drops far enough, you owe the broker money even after the shares are sold.
  • Margin calls force selling at the worst time. If your equity falls below the broker's maintenance margin (typically 25–30% of position value), the broker can liquidate your positions without your consent, usually at a loss.
  • Interest accrues every day you hold. A small daily charge becomes meaningful over weeks or months and turns marginal winners into losers.
  • Dividends received do not always offset losses. A stock can drop more than the dividend it pays, even on the ex-date.
  • This calculator ignores taxes, slippage, and gaps. Real trades have these costs. They make break-even harder to hit than the math here suggests.

If you're new to margin trading, consider trading with cash first and only adding leverage once you have a documented track record showing the strategy works in your hands across many trades.

A note on these calculations. Numbers shown are mathematical outputs of the inputs you provide, not predictions or recommendations. diviStock provides research and educational content only and is not a registered investment advisor. The calculator does not account for taxes, slippage, dividend receipts, currency conversion, partial fills, or stop-loss execution. Real-world results will differ. Past performance does not predict future results. See our Financial Disclaimer before acting on any of this information.

diviStock provides research and educational content only. We are not registered investment advisors. The information and alerts provided are NOT financial, investment, tax, or legal advice. All investing involves risk including the potential loss of principal. Past performance, including 10-year backtest results, does not guarantee or predict future results. Always do your own research and consult a qualified financial advisor before making investment decisions. Use stop losses. By using this service you acknowledge that diviStock is not responsible for any trading losses you incur.