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;

www.databank.rbs.com

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)