Advanced Late Payment Interest Calculator

Advanced Late Payment Interest Calculator

Calculate interest and admin fees on overdue invoices using multiple calculation methods

Flexible Late Payment Calculator — Create customized interest calculations for your unpaid invoices:

  • Choose from annual interest rates, monthly rates, or fixed percentage calculations
  • Apply compound interest for escalating charges on long-term unpaid invoices
  • Add optional admin fees to cover your collection costs
  • Calculate multiple invoices at once with detailed breakdowns for each

Use this calculator to determine fair interest charges, incentivize on-time payments, and recover costs associated with late payments.

Interest Calculation Settings

Annual Interest Rate
% per year

Standard annual interest rate applied to overdue amount

Monthly Interest Rate
Fixed Percentage
Apply Compound Interest (Monthly)

When enabled, interest will compound monthly, applying interest to previously accrued interest

Apply Fixed Admin Fee
$

Fixed administration fee applied to each late invoice

Invoice Details

Invoice 1
(or today's date if not paid yet)
$

Automatically add late fees and interest to your Xero or QuickBooks invoices

Save hours manually calculating late fees & interest.

Applied in bulk, and automatically when going overdue.

Flexible and custom to your payment terms.

This calculator provides an estimate based on the information provided. For exact figures, please consult a financial professional, or an expert from Paidnice.