Compound Interest Calculator

Add one line for each part of an invoice or debt. Additional lines inherit the annual rate, dates and compounding frequency from Calculation Line 1 by default.

A = P(1 + r/n)nt
The title and description are included in the PDF. 0 / 200

Calculation lines

Combined totals

Total principal £0.00
Total interest £0.00
Total accrued amount £0.00
How compounding works: P is the starting principal, r is the annual interest rate expressed as a decimal, n is the number of compounding periods per year, and t is the elapsed time in years. Interest is added to the balance at each compounding period, so later interest is calculated on the original principal plus interest already accumulated. Each line uses Actual/365, where t = elapsed days / 365 and nt = n × t.

The interest rate used in this calculation was calculated using figures obtained from the Bank of England.