Loan Calculator: Payment, Total Interest and APR

Solve either way: the payment for a loan amount, or the loan amount for a payment — with the APR after fees.

Enter your numbers

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%
years
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Origination or processing fees, used for the APR.

Results

How this calculator works

A fixed-rate loan is repaid in equal monthly payments. Each payment first covers that month’s interest (balance × monthly rate); the rest reduces the balance, so early payments are mostly interest and later ones mostly principal.

To find how much you can borrow, the same formula is run backwards from the payment. If you pay up-front fees, you receive less cash than you repay on, so the APR — the rate that matches the cash you actually get to the payments you make — is higher than the stated rate.

Payment = L × r ÷ (1 − (1 + r)^−n) Loan = Payment × (1 − (1 + r)^−n) ÷ r APR = rate i where Payment × (1 − (1 + i)^−n) ÷ i = L − Fees (× 12)

Assumptions and tips

  • Fixed rate, monthly payments, no prepayment penalty.
  • If fees are added to the loan instead of paid up front, enter the larger loan amount.

Worked example

Using the default values in the calculator above:

InputValue
What do you want to find?Monthly payment
Loan amount$25,000
Interest rate7.5 %
Term5 years
Up-front fees$0

ResultValue
Monthly payment$500.95
Total interest$5,057
Loan amount$25,000
Total of payments$30,057
Number of payments60
APR (with fees)7.5 %

Amortization by year:

  • Year 1: interest $1,730, principal $4,282, balance $20,718
  • Year 2: interest $1,397, principal $4,614, balance $16,104
  • Year 3: interest $1,039, principal $4,972, balance $11,132
  • Year 4: interest $653, principal $5,358, balance $5,774
  • Year 5: interest $237, principal $5,774, balance $0

Step by step:

  1. Monthly rate = 7.5% ÷ 12 = 0.625%, n = 60 payments
  2. Payment = $25,000 ÷ 49.905 = $500.95
  3. Total interest = $500.95 × 60 − $25,000 = $5,057

Monthly payment on a $10,000 loan

Payments for $10,000 at common rates and terms — scale up for larger loans.

Rate and termMonthly paymentTotal interest
6% · 3 years$304.22$952
8% · 3 years$313.36$1,281
6% · 5 years$193.33$1,600
8% · 5 years$202.76$2,166
10% · 5 years$212.47$2,748
12% · 5 years$222.44$3,347
15% · 5 years$237.9$4,274
8% · 7 years$155.86$3,092

Common mistakes to avoid

  • Looking only at the rate and ignoring origination fees — compare APRs instead.
  • Stretching the term to lower the payment without checking how much more interest it adds.

Frequently asked questions

What is the monthly payment on a $25,000 loan?

At 7.5% for 5 years it is about $501 a month, with about $5,057 of total interest.

What is the difference between interest rate and APR?

The interest rate is the cost of borrowing the principal. The APR adds fees spread over the loan, so it shows the full yearly cost.

Sources

Last reviewed: 2026-10-27 · How we build and check calculators