Loan Calculator
The monthly payment, total interest, and total cost for any fixed-rate loan — mortgage, auto, personal, or business.
Your loan
Works for any fixed-rate loan — enter your specific amount, rate, and term.
Monthly Payment
$406/mo
Fixed for the full loan term
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Last updated: August 6, 2026 · Reviewed by the DoCalc team
What Is a Loan Calculator?
Every fixed-rate, fully amortizing loan — whether it's a mortgage, a car loan, a personal loan, or a business loan — uses the exact same underlying math to turn a loan amount, interest rate, and term into a monthly payment. This calculator is the general-purpose version of that math: enter any three of those inputs and get the payment, total interest, and total cost, without needing a loan-type-specific calculator for a quick first estimate.
The Formula
Where M is the monthly payment, P is the loan amount (principal), r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (term in years × 12). This is the standard loan amortization formula, used across virtually every fixed-rate consumer and business loan.
Worked Example
A $20,000 loan at 8% over 5 years:
Over the life of this loan, interest adds about 21.7% on top of the original amount borrowed — a useful sanity check for whether a loan's total cost matches what you expected from its advertised rate.
When to Use a Loan-Type-Specific Calculator Instead
| Situation | Better tool |
|---|---|
| Buying a home, want taxes/insurance/PMI included | Mortgage Payment Calculator |
| Want the full year-by-year payment breakdown | Amortization Calculator |
| Loan has an origination fee to account for | Personal Loan Calculator or APR Calculator |
| Financing a vehicle with trade-in/sales tax | Auto Loan Calculator |
| Modeling extra payments to pay off early | Loan Payoff Calculator |
Who Should Use This Calculator
Use it if you want a fast, generic payment estimate for any fixed-rate loan and don't need loan-type-specific extras like taxes, fees, or trade-in values factored in.
Use a more specific calculator if your loan has extra costs (fees, taxes, insurance) that meaningfully change the real payment — the table above points to the right one.
Common Mistakes to Avoid
The most common mistake is comparing two loan offers by interest rate alone — a lower rate with a longer term can still cost more in total interest than a higher rate with a shorter term. Always compare total interest (or total cost) alongside the monthly payment, not the rate in isolation. A second mistake is forgetting that this calculator assumes a fixed rate for the entire term — a variable-rate loan's real payment will change if rates move during the loan's life.
Worth knowing: the same $20,000 loan at 8% costs roughly $4,332 in interest over 5 years, but only about $2,169 over 3 years, or nearly $9,000 over 10 years — term length changes total interest far more than most borrowers expect.
Frequently Asked Questions
What does this Loan Calculator work for?
Any fixed-rate, fully amortizing loan — mortgages, auto loans, personal loans, business loans, and more all use the same underlying payment formula, so this calculator works for any of them as a quick, general-purpose starting point.
How is my monthly payment calculated?
Using the standard loan amortization formula, based on your loan amount, annual interest rate, and term. It assumes a fixed rate and equal monthly payments for the full term.
What's the difference between this and the Amortization Calculator?
This calculator gives you the quick top-line numbers — payment, total interest, total cost. The Amortization Calculator shows the full year-by-year schedule of how each payment splits between principal and interest.
Does this include fees like origination charges?
No — this calculates payment based purely on the loan amount and rate. If your loan has fees, check the APR Calculator to see how those fees affect the loan's true annualized cost, or the Personal Loan Calculator, which models an origination fee directly.
Can I use this for a loan with a variable rate?
This models a fixed rate for the entire term. For a variable or adjustable-rate loan, run the calculator separately for each rate period using that period's rate to estimate payments during that stretch.
Conclusion
The same three numbers — amount, rate, term — drive the payment on almost any loan you'll ever take out. Once you know how they interact, checking a loan offer takes seconds instead of guesswork.