Loan Repayment Calculator: Monthly Payment, Interest and Total Cost
A loan repayment calculator estimates the payment required to repay a fixed-rate installment loan. It is useful for personal loans, student loans, equipment loans, and other debts with regular monthly payments.
Quick answer
A lower interest rate or shorter payoff period reduces total interest, but a shorter term usually raises the monthly payment. Compare both payment affordability and lifetime cost.
At a glance
- What it calculates
- Calculate a fixed monthly loan payment, total interest, and total repayment cost.
- Who it is for
- US borrowers comparing fixed-rate loan offers by payment, term and total interest.
- Coverage
- United States (federal rules; state and local rules vary)
- Data and assumptions
- A fully amortising fixed-rate loan with equal monthly payments and no origination fees or insurance.
- Cost
- Free, no signup, calculations run in your browser
- Last reviewed
- 2026-07-09
Calculator
How to use this calculator
- Enter the amount borrowed.
- Add the annual interest rate and repayment term.
- Optionally enter an extra monthly payment.
- Compare the monthly payment, total interest, and estimated payoff time.
Explanation
What it is
A loan repayment calculator estimates the payment required to repay a fixed-rate installment loan. It is useful for personal loans, student loans, equipment loans, and other debts with regular monthly payments.
How it works
The monthly payment uses the standard amortization formula M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1]. The calculator assumes a fixed rate and equal monthly payments.
When to use it
Use it when comparing fixed-rate loan quotes, or checking what a shorter term or extra payment does to total interest.
Limitations
- Origination fees, insurance and prepayment penalties are excluded from the payment.
- Variable-rate and interest-only structures are not modelled.
- Payment timing and servicer rounding can shift interest slightly.
Key terms
- APR
- Annual percentage rate, a yearly measure of borrowing cost.
- Principal
- The original amount borrowed.
- Term
- The scheduled length of the loan.
- Amortization
- Gradual repayment through principal and interest payments.
- Extra payment
- An amount paid above the required payment to reduce debt faster.
Formula
The monthly payment uses the standard amortization formula M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1]. The calculator assumes a fixed rate and equal monthly payments.
Worked example
A $25,000 loan at 8% for five years produces a fixed scheduled payment. Adding an extra monthly amount can shorten the payoff period and reduce total interest.
FAQ
How much is the monthly payment on a $25,000 loan?
The payment depends on the interest rate and term. For example, a five-year loan at 9.5% has a payment of roughly $525 per month before fees.
Does paying extra reduce the interest I pay?
Usually yes. When a lender applies extra payments to principal without a prepayment penalty, the balance falls faster and less interest accrues.
What is the difference between interest rate and APR?
The interest rate is the cost charged on the balance. APR may include certain lender fees and is designed to make loan costs easier to compare.
Can I use this for a variable-rate loan?
This calculator assumes a fixed rate. A variable-rate loan may have changing payments and a different total cost.
Does the calculator include origination fees?
No. Add fees separately when comparing the cash received and total borrowing cost.
What happens if I choose a longer loan term?
The required payment generally falls, but total interest usually rises because the balance remains outstanding longer.
Common mistakes
- Comparing only monthly payments.
- Ignoring origination fees or variable rates.
- Assuming every extra payment goes to principal.
- Extending the term without checking total interest.
Tips
- Compare APR and total repayment, not only rate.
- Confirm whether prepayment penalties apply.
- Direct extra payments to principal when permitted.
- Keep an emergency reserve before accelerating aggressively.
Sources and editorial review
Educational estimates only; not personalized financial, tax, legal, lending, investment, or insurance advice.