Loan Payment Calculator
Monthly instalment, total paid and total interest on a loan repaid in equal payments.
Results
Monthly payment
673.57
Total paid
242,484.13
Total interest
92,484.13
What this tool does
This is the standard annuity calculation used for mortgages and consumer loans with a fixed rate and equal monthly instalments. It covers capital and interest only: insurance, fees, taxes and rate changes on a variable-rate loan are not included.
Formula
PMT = C × i ÷ (1 − (1 + i)^−N) , i = annual rate ÷ 12
Variables
| Symbol | Meaning | Unit |
|---|---|---|
p | Loan amount | — |
r | Annual interest rate | % |
t | Term in years | — |
PMT | Monthly payment | — |
TP | Total paid | — |
TI | Total interest | — |
Worked example
- Loan amount150,000
- Annual interest rate3.5 %
- Term in years30
- Monthly payment673.57
- Total paid242,484.13
- Total interest92,484.13
Limitations
- This is an informational calculator, not personalised financial advice. Rates, fees, taxes and contract conditions vary between institutions and countries.
- The tool works with whatever currency you use for the inputs; it does not convert between currencies.
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.
Frequently asked questions
Why is the total interest so much larger than I expected?
Because interest is charged on the outstanding balance every month, and on a long loan that balance stays high for years. On a thirty-year loan, the early payments are mostly interest and only a small part reduces the debt. Shortening the term or paying a little extra early has a much bigger effect than most people assume.