Question 1

What is the simple interest formula?

Accepted Answer

SI = (P × R × T) / 100, where P is principal, R is annual rate in percent, and T is time in years.

Question 2

What is the compound interest formula?

Accepted Answer

A = P × (1 + r/n)^(n×t), where r is the annual rate as a decimal, n is compounding frequency per year, and t is years. CI = A − P.

Question 3

Which gives more: simple or compound interest?

Accepted Answer

Compound interest always gives more than simple interest (for rate and time > 0), because interest earns interest in later periods.

Question 4

Is this interest calculator free?

Accepted Answer

Yes, completely free with no sign-up. All calculations happen in your browser.

Interest Calculator

Simple Interest