usefulweb.site Loan Amortization Calculator

Everyday calculators

Loan Amortization Calculator

Annuity, linear or interest-only loans: schedule, extra payments, fixed-rate balance, APR.

Shown in results only; no conversion.

% per year

Borrowing rate (Sollzins). The rate per period is this ÷ payments per year.

years
% per year

Optional, common in Germany (anfängliche Tilgung): payment per year = loan × (interest rate + this rate). The term then follows from the payment and the Term field is ignored.

Optional. The first payment is due one period later; dates are added to the schedule.

years

Optional (Zinsbindung): shows the balance still owed when the fixed rate ends.

Processing or broker fees paid at payout. They raise the APR, not the nominal rate.

One-off extra payments

Paid together with the regular payment number you enter (e.g. 12 = end of the first year for monthly payments).

One-off extra payments
#Payment numberExtra amount
1
2
3

Optional, e.g. an annual special repayment (Sondertilgung).

payments

Optional; empty = until the loan is repaid.

Try an example: Mortgage 300,000 at 3.8%, 2% initial repayment, 10-year fixed rate · Car loan 20,000, 5 years at 6.9% with 400 fees · Linear loan 120,000 over 10 years, quarterly

How it works

Calculates the payment and the complete amortization schedule of an annuity, linear (constant principal) or interest-only loan, including one-off and recurring extra payments, the remaining balance at the end of a fixed-rate period, the effective annual rate and the APR with up-front fees. Download the schedule as CSV.

  • Rate per period i = nominal annual rate ÷ payments per year (the usual convention for German and most European loans).
  • Annuity payment A = L·i ÷ (1 − (1 + i)^−n), rounded to the cent; with an initial repayment rate t instead: A = L × (rate + t) ÷ payments per year, and the term follows from A.
  • Each period: interest = balance × i (rounded to the cent); principal = A − interest (annuity), L ÷ n (linear) or 0 until the last payment (interest-only). The last scheduled payment clears any remaining cents.
  • Extra payments reduce the balance on top of the regular payment. Annuity loans keep the payment and finish earlier; linear and interest-only loans keep their principal plan and pay less interest.
  • Remaining balance at the end of the fixed-rate period = balance after the last payment inside that period.
  • Effective annual rate (no fees) = (1 + i)^m − 1. APR: the rate X solving Σ payment_l × (1 + X)^(−t_l) = loan − up-front fees, with t_l measured in years of 12 standard months, as in the equation of the PAngV annex (EU Consumer Credit Directive). This is an approximation: real offers count exact days, may add account fees or insurance, and lenders round to two decimals.

Sources

For scripts and AI agents

  • JSON API: POST https://loanamortizationcalculator.usefulweb.site/api/v1/calculate (same calculation as this page)
  • Interface description: OpenAPI 3.1 · AI guide: llms.txt
  • MCP server (Streamable HTTP): https://loanamortizationcalculator.usefulweb.site/mcp · tool name loan_amortization_calculator
Example request
curl -s -X POST https://loanamortizationcalculator.usefulweb.site/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{"principal":300000,"currency":"EUR","ratePercent":3.8,"loanType":"annuity","initialRepaymentPercent":2,"frequency":"monthly","startDate":"2026-11-01","fixedRateYears":10,"upfrontFees":0,"recurringExtra":5000,"recurringEvery":12,"recurringFrom":12}'
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