Loan Calculator
Compare monthly payments and total interest for amortizing, equal-principal and interest-only (bullet) loans, with a full monthly schedule and optional grace period.
Monthly payment
1,432
Total interest 215,680 · Total paid 515,680
| Repayment | First payment | Total interest | Total paid |
|---|---|---|---|
| Equal payments | 1,432 | 215,680 | 515,680 |
| Equal principal | 1,833 | 180,571 | 480,571 |
| Interest-only | 1,000 | 360,000 | 660,000 |
Monthly schedule
| # | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | 1,432 | 432 | 1,000 | 299,568 |
| 2 | 1,432 | 433 | 999 | 299,135 |
| 3 | 1,432 | 435 | 997 | 298,700 |
| 4 | 1,432 | 436 | 996 | 298,264 |
| 5 | 1,432 | 438 | 994 | 297,826 |
| 6 | 1,432 | 439 | 993 | 297,387 |
| 7 | 1,432 | 441 | 991 | 296,946 |
| 8 | 1,432 | 442 | 990 | 296,504 |
| 9 | 1,432 | 444 | 988 | 296,060 |
| 10 | 1,432 | 445 | 987 | 295,615 |
| 11 | 1,432 | 447 | 985 | 295,168 |
| 12 | 1,432 | 448 | 984 | 294,720 |
Assumes a fixed rate; each month’s interest is the remaining balance × annual rate ÷ 12, rounded. Real loans can differ with daily interest calculation, variable rates and early repayment fees.
Guide
Key points
- Compares monthly payments and total interest for three repayment methods.
- Equal principal has the lowest total interest; interest-only the highest.
- A grace period lowers early payments but raises total interest.
Repayment methods
- Equal payments (amortizing): the same payment every month — the most common for mortgages.
- Equal principal: the same principal every month plus interest on the balance, so payments start high and fall. Lowest total interest.
- Interest-only (bullet): interest each month and the whole principal at the end. Highest total interest; common for short-term loans.
Example: 100,000,000 at 4% over 30 years costs about 477,000 a month and 71.9M in interest with equal payments, 611,000 in the first month and 60.2M in interest with equal principal, and 333,000 a month and 120M in interest interest-only.
Grace period
During a grace period you pay only interest. It lowers early payments, but the balance doesn’t shrink, so total interest goes up and later payments are larger.
Paying less interest
- Prepay when you can — many loans drop early repayment fees after a few years.
- If rates fall, compare refinancing offers.
- A longer term lowers the monthly payment but raises total interest considerably.
FAQ
Equal payments or equal principal?
Equal principal costs less interest overall but starts with higher payments. Equal payments are easier to budget.
Why does my bank's figure differ slightly?
Banks may use daily interest, variable rates and actual payment dates, so small differences are normal.