Skip to content
Ryan Duguid
Tools Rates Evaluations Evidence About Contact
  1. Home
  2. Tools
  3. Monthly loan payment calculator

Monthly loan payment calculator

Fixed monthly payment, first-payment interest and principal, and estimated total interest, with no fees or balloon.

Published 20 September 2026. Last reviewed 27 September 2026.

Monthly loan payments inputs
Enter the inputs and calculate.

Sources applied

  • Formula: payment = principal × r / (1 − (1 + r) raised to −n), with r the monthly rate and n the number of payments; at zero interest, payment = principal / n. Payments in arrears, no fees or balloon.
  • Figures: supplied by you. No statutory rate or threshold is applied. The interest rate is yours, not a market or lender rate. No external source is applied.

How it works

For fixed monthly interest r and n payments: payment = principal × r / (1 − (1 + r) raised to −n). At zero interest, payment = principal / n. Payments are in arrears, with no fees or balloon. Interest is estimated from unrounded payments; lender rounding and daily accrual can differ.

Loan reconciliation checklist

One of the nine business calculators. Calculations run in this browser. The calculator code does not send your inputs to a server or save them automatically. To check, disconnect from the internet once the page has loaded, then calculate.

Planning estimates in AUD. Confirm tax treatment, liability amounts and dates separately. Amounts round to the nearest cent, with exact half cents rounded up.

Written by Ryan Duguid in his own time and on his own equipment. He is a Provisional CA ANZ Member. CA ANZ has not endorsed this site or its tools.

Tools Rates Evaluations Evidence About Contact Privacy and site use

Ryan Duguid is not a registered tax agent or BAS agent. Nothing here is tax, legal or financial advice. Computational outputs are review aids for a qualified professional, not compliance determinations, and lodgement decisions stay with a human.

Changelog GitHub Related resources Machine-readable index

Ex fide fiduciaEx fide fiducia, Latin for from faith comes confidence

Ryan Duguid, ABN 59 834 031 764

duguid.com.au/tools/business-calculators/loan/


      

Page text could not be loaded. Open full text or select Human to return.