The payment stays almost even each month, making budgeting easier. This is common for mortgages.
Finance Utility
Loan Interest Calculator
Estimate your monthly payment, total interest and repayment schedule from a loan amount, rate and term.
Monthly payment
Calculate payments for amortized, equal-principal and interest-only loans.
Compare repayment types
See how payment pressure and total interest change by repayment method.
Export schedule
Review principal, interest and balance by month, then download a CSV file.
Loan Calculator
Ready
Loan details
Enter the amount, rate, term and repayment type to estimate the schedule.
Result
Waiting
Calculation Result
No result yet.
Enter loan details on the left to show the summary and monthly schedule here.
Repayment Types
Repayment Type Comparison
The same amount and rate can produce different monthly pressure and total interest.
You repay the same principal every month, so interest gradually falls. Early payments are higher but total interest is usually lower.
You pay interest during the term and repay principal at maturity. A clear payoff plan is important.
Loan Interest Calculator
Compare fixed-payment, equal-principal and interest-only loan schedules. Check monthly payments, total interest and the final payment before exporting a full CSV.
Who this helps
- Borrowers comparing repayment methods
- Readers estimating fixed-rate payment schedules
When to use this tool
- Interest-only maturity
- Equal principal
From input to a checked result
- 1
Enter a positive whole-number principal.
- 2
Enter an annual rate from 0 to 100%.
- 3
Select 1–50 years or 1–600 months.
- 4
Choose a repayment method and calculate.
- 5
Review the final payment and totals, then export all instalments if needed.
Interest-only maturity
- Input
- Principal 12,000; annual rate 12%; 12 months
- Result
- Monthly interest 120; final payment 12,120; total paid 13,440
The final payment includes principal and one month of interest, not all lifetime interest.
Equal principal
- Input
- Principal 12,000; annual rate 12%; 12 months
- Result
- First payment 1,120; last 1,010; total interest 780
Principal falls by 1,000 each month; at 0% both amortizing methods pay 1,000 monthly.
How it works
Monthly rate is annual rate / 12. Fixed payment is P × r(1+r)^n / ((1+r)^n−1), with P/n at zero interest. Equal principal pays P/n plus interest on the remaining balance. Interest-only pays monthly interest and repays principal at maturity.
Limitations
- The rate stays fixed and each month is treated equally.
- Fees, insurance, tax, grace periods and early repayment are excluded.
- Whole-unit displayed amounts may not sum to the unrounded total; CSV uses rounded rows.
- Principal is limited to 1–1 trillion in the displayed currency; this is a tool limit, not lending eligibility.
Your data
Loan values are calculated in this browser and are not saved to the server. CSV files contain your entered loan scenario.
References
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Frequently asked questions
Does the CSV include every month?
Yes. Export includes the entire term even when the table preview is shorter.
What happens at 0%?
Amortizing methods divide principal evenly. Interest-only has zero interim payments and repays principal at maturity.
Why does a lender schedule differ?
Actual day counts, due dates, rounding and charges can differ from these assumptions.