ToolForage.
LOANS CALCULATOR

Loan Calculator

Enter a fixed-rate loan term in years and months or total months. Add an extra monthly payment to compare interest saved, time saved and the final installment.

Calculator

%
years
months
months
Added to every scheduled monthly payment from the start; zero keeps the original plan.
YOUR RESULTS
Scheduled monthly payment299.71
Payment with extra
299.71
Total interest
789.52
Total paid
10,789.52
Payoff time
36 months
Interest saved
0.00
Original scheduled term
36 months
Time saved with extra payments
0 months
Final payment with the extra plan
299.71

The original term is 36 monthly payments. With the entered extra principal, payoff takes 36 payments; the last payment is 299.71.

Remaining loan balance

Amounts use the same currency as your inputs.

Balance
03.4K6.8K123Year

Year 3

Principal paid in year
3,500.97
Interest paid in year
95.54
Remaining balance
0.00

Each point shows the remaining balance after payments for that year. The final year may contain fewer than 12 payments.

Annual amortization summary
Annual amortization summary
YearPrincipal paid in yearInterest paid in yearRemaining balance
13,168.46428.046,831.54
23,330.57265.943,500.97
33,500.9795.540.00
Page guide

Scheduled payments and extra repayments

The scheduled payment repays principal and interest over the stated term. Payment with extra is the planned monthly outflow until a smaller final payment. Total interest, total paid, and payoff time reflect the extra-payment plan; interest saved compares it with the same loan without extra payments. Original scheduled term is the combined number of months. Time saved compares payoff counts with and without the extra amount. Final payment is the amount needed to clear the last balance, including that month’s interest; it may be smaller than the planned monthly outflow.

For a housing budget that includes property tax, insurance, and association fees, the Mortgage Calculator adds those estimates to principal and interest.

The formula

M = P × [r(1 + r)ⁿ] ÷ [(1 + r)ⁿ − 1]

P is principal, r is the monthly interest rate, and n is the number of monthly payments. When the rate is zero, payment is principal divided by n. The schedule applies interest to the remaining balance each month before subtracting principal. A years-and-months term uses n = 12 × whole years + additional months, from 1 to 600. The alternate total-month entry represents the same term. Changing the entry format converts a valid term; it does not alter payment frequency. The final installment is capped at remaining principal plus monthly interest.

A 10,000 loan for three years

For 10,000 at 5% over 36 months, the scheduled installment is about 299.71. Adding 100 each month reduces modeled payoff from 36 to 27 payments and saves about 206.81 in interest. The last payment is smaller than the planned 399.71 monthly outflow.

How to use this calculator

  1. Enter principal and the fixed annual contract rate rather than an APR that already includes fees.
  2. Choose Years and months or Total months for a term from 1 to 600 monthly payments. Optionally enter an extra monthly amount.
  3. Review live scheduled payment, actual payoff time, months and interest saved, final installment and annual balances.

How amortization changes each month

A level payment stays constant, while its split changes. Early payments contain more interest because the outstanding balance is larger. Later payments direct more money to principal.

Extra principal lowers the balance sooner. The calculator keeps the required scheduled payment unchanged and applies the extra amount every month until payoff.

Compare loan offers on total cost

A lower payment can result from a lower rate, a longer term, or both. A longer term often increases total interest even when it makes each payment easier to manage.

Fees are not included here. Compare the annual percentage rate and disclosures from the lender, not just an advertised interest rate.

Terms shorter than a whole year

Six months is entered as zero whole years and six additional months, or six total months. A term of three years and six months is 42 payments. The maximum is 50 years exactly; adding months beyond that exceeds the supported term. Switching formats converts a valid entry without changing its duration.

Assumptions & limitations

What this calculation assumes

  • Fixed nominal annual interest divided into twelve monthly periods.
  • Payments are made on time at the end of each month.
  • Extra payments go directly to principal without a prepayment charge.

What to keep in mind

  • Origination fees, taxes, insurance, late charges, and changing rates are excluded.
  • Actual lender rounding and payment dates can produce small differences.
  • The result is an estimate, not a lending offer.

Common questions

Does an extra payment reduce the required payment?

This model keeps the scheduled payment unchanged and shortens the payoff time. A lender may handle recasting differently.

Why is the final payment smaller?

The regular amount can exceed the last balance plus interest, so the schedule uses only what is needed to reach zero.

Can I use this for weekly payments?

This calculator models monthly payments.

Can I use this for a student loan?

It can estimate a fixed-rate loan already in repayment with monthly installments. It does not model in-school or grace-period interest, deferment, capitalized interest, income-driven payments, or forgiveness. Enter the repayment balance and terms that match your agreement.

Can I enter a term such as 18 months?

Yes. Use Total months and enter 18, or enter one whole year and six additional months. Monthly repayment and the fixed nominal rate model remain the same.

Sources & further reading

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