Methodology Compound Interest Calculation (Updated to June 2022)

A formula that can be used for calculating compound interest

A = P(1 + r/n)nt ; R = r * 100

Where:
A= Total Accrued Amount (principal + interest)
P = Principal Amount
I = Interest Amount
R = Rate of Interest per year in decimal ; r = R/100
t = number of periods
n = compounding period

UK Base Interest Rates source
Bank of England Base Rate

XLS File of Base Rate changes since 1664 to June 2022

So for example if we want to calculate interest on £100,000 over a period of 4 years and 8 months based on an interest rate of 4.0% over the base of 0.5% over differing compound periods;
Compounded annually;
A = 100,000 ( 1 + 0.045/1)^4.67 = £122,821.10
A = £122,821.10

Compounded Monthly;
A = 100,000 ( 1 + 0.045/12)^56 = £123,319.40
A = £123,319.40

Compounded Daily
A = 100,000 ( 1 + 0.045/365)^1704 = 123,376.30
A = £123,376.30
Please note : simplification this calculation leap years re-calculate if important
(^ indicates to the power of)