Formulas
How to Use
Enter the initial amount and the annual rate of interest.
Enter time in years and choose how often interest is compounded.
See CI, total amount and how much more you earn compared to simple interest.
Frequently Asked Questions
A = P × (1 + R/n/100)^(n×T), where P = Principal, R = Annual Rate %, n = number of times compounded per year, T = Time in years. CI = A − P.
Interest is calculated and added twice a year. The formula becomes A = P × (1 + R/200)^(2T). The effective rate is slightly higher than the nominal annual rate.
For 2 years: CI − SI = P × (R/100)². For 3 years: CI − SI = SI × (R/100 + R²/10000 + ...). These shortcuts are frequently tested in SSC and IBPS exams.
Effective rate = (1 + R/200)² − 1 × 100 = (1.05)² − 1 = 10.25% per annum. This is higher than the nominal 10% because interest compounds twice a year.