Loan Payment Calculator

Before you calculate

Use this calculator when you want a quick fixed-rate amortizing loan estimate before comparing lender disclosures, APRs, fees, taxes, insurance, escrow, underwriting, or product terms elsewhere. Use APR when fees need to be folded into a rate-style comparison, Amortization when you need a payment schedule, Personal Loan for fee and cash-received context, and Mortgage Payment when housing costs such as taxes, insurance, PMI, or escrow matter.

Formula summary

The app converts Annual rate to a monthly decimal rate with annualRate / 100 / 12 and converts Term in years to total months with termYears * 12. If the monthly rate is 0, Monthly payment equals loanAmount / months. Otherwise it uses PMT = P * m / (1 - (1 + m)^-n), where P is loan amount, m is monthly rate, and n is total months. Total paid equals the full-precision monthly payment times total months, and Total interest equals Total paid minus loan amount.

Worked example

Example: $200,000 at 5 percent for 30 years

With the default inputs, a $200,000 loan amount, 5 percent annual rate, and 30-year term become 360 monthly payments at a monthly rate of about 0.0041667. The calculator reports a $1,073.64 monthly payment, $386,511.57 total paid, and $186,511.57 total interest. In the zero-rate fixture, $12,000 at 0 percent for 1 year divides evenly into 12 payments of $1,000.00, with $12,000.00 total paid and $0.00 interest.

The example shows how the fixed-payment formula separates principal, rate, term, total paid, and interest. It does not quote a lender, calculate APR, approve credit, disclose legal loan terms, or include taxes, insurance, escrow, fees, or personal borrowing advice.

Assumptions

• The loan amount, annual rate, and term stay fixed. The calculator models a level monthly principal-and-interest payment and does not model variable rates, promotional rates, negative amortization, interest-only periods, balloon payments, late fees, extra payments, or payment-calendar differences.
• The annual rate input is a user-entered rate assumption divided by 12 for the payment formula. It is not automatically a lender APR and does not include finance charges, origination fees, broker fees, points, closing costs, taxes, insurance, escrow, mortgage insurance, credit insurance, add-on products, lender credits, or rebates.
• Scoped independent comparator checks pass 4 of 4 scoped fixtures for overlapping monthly payment, total paid, and total interest outputs. CFPB, Regulation Z, lender, and local regulatory sources are needed before making APR, Truth in Lending, Loan Estimate, finance charge, amount financed, total-of-payments, escrow, tax, insurance, prepayment, variable-rate, approval, or legal-disclosure claims. Results are educational estimates, not financial, tax, legal, lending, credit, mortgage, consumer-rights, regulatory, or personalised advice.

Common mistakes to avoid

• Comparing only the monthly payment. A longer term can reduce the payment while increasing total interest, so monthly payment and total interest should be read together.
• Treating the entered annual rate as the same thing as APR. Real APR and disclosure figures may include fees or other finance-charge rules that this three-input calculator does not model.
• Using this as a full mortgage payment, lender quote, approval, disclosure, or payoff schedule. Taxes, homeowners insurance, mortgage insurance, HOA dues, escrow, prepayment rules, and amortization schedules need separate tools or official documents.

Methodology and sources

This calculator is an original implementation based on documented formulas, app-specific assumptions, deterministic fixtures, edge cases, rounding policy tests, and internal validation. It is not copied from a single source.

Outputs are checked with deterministic fixtures, edge cases, rounding policy tests, and internal independent comparator checks where overlapping outputs are available. The result remains an educational estimate, not a quote, approval, tax answer, or personalised advice.

Formula version 2026.05.20. The version marks the calculation logic and validation fixture set used for this estimate.

• CFPB APR, finance charge, Truth in Lending, amount financed, total of payments, and payment-disclosure materials should be used when copy compares the calculator rate with real lender APRs or disclosures.
• CFPB Loan Estimate and principal-and-interest versus total monthly payment guidance should be used when copy discusses mortgage closing costs, taxes, homeowners insurance, mortgage insurance, escrow, or total housing payment boundaries.
• eCFR Regulation Z, lender disclosures, and relevant local regulator sources should be used when copy makes legal, jurisdiction-specific, product-specific, prepayment, variable-rate, negative-amortization, or consumer-credit disclosure claims.

Estimate only

The result is educational and is not financial, tax, legal, lending, investment, or regulated advice. Real provider terms, fees, rates, taxes, and personal circumstances can change the final answer.

Formula and help: read the full loan payment calculator methodology notes.

Related reading

• Monthly loan payments explained
• How Calcs.finance validates calculator formulas
• Estimate limitations and not-advice disclaimer

When another calculator fits better