Margin Interest Calculator
Calculate the true cost of borrowing on margin. See how interest accumulates with daily compounding and how monthly repayments can reduce your total interest expense.
What is margin interest?
Margin interest is the cost of borrowing money from your broker to buy securities. When you buy on margin, you're using leverage — putting up a percentage of the purchase price while your broker lends you the rest. Interest accrues daily on the loan balance and compounds over time. Unlike a standard loan, margin loans typically have no fixed repayment schedule, but interest adds up quickly if left unpaid.
How it works: Your broker charges a stated annual interest rate on your margin loan. Interest is calculated daily ( rate ÷ 365 ) and typically compounds daily, meaning you pay interest on previously accrued interest. This calculator shows you the total cost over your holding period and lets you compare the impact of making monthly repayments.
Margin Interest Calculator — Cost of Borrowing on Margin
Free margin interest calculator. Calculate interest costs on margin loans with daily compounding. Compare scenarios with and without monthly repayments.
Loan Balance Over Time
Monthly Breakdown
| Month | Interest Accrued | Ending Balance | Balance w/o Repayment |
|---|---|---|---|
| 1 | $66 | $10,066 | $10,067 |
| 2 | $66 | $10,132 | $10,134 |
| 3 | $67 | $10,199 | $10,202 |
| 4 | $67 | $10,266 | $10,270 |
| 5 | $68 | $10,334 | $10,339 |
| 6 | $68 | $10,402 | $10,408 |
| 7 | $69 | $10,471 | $10,478 |
| 8 | $69 | $10,540 | $10,548 |
| 9 | $70 | $10,610 | $10,618 |
| 10 | $70 | $10,680 | $10,689 |
| 11 | $70 | $10,750 | $10,761 |
| 12 | $71 | $10,821 | $10,833 |