Compound Interest Calculator

This calculator shows how much money you will have after a period of time, based on initial amount invested, interest rate, and the number of times compounded.
Amount Invested (P): $

Annual interest rate (r): %

Period of Time (t):

Compound Frequency (n):
(Annual=1, Semi-Annual=2, Quarterly=4, Monthly=12)


Interest and Principal  (A): $

* When entering the percentage value, input the percentage without a decimal  -- i.e. 5% is 5; the calculator considers the decimal
Principal: The money you invest with a bank or investment company.
Interest rate: The amount of money you get paid yearly for every dollar you invest
Time: Length of time money will be in the bank or with the investment company.
Compound Frequency: How often interest is calculated.

Compounded yearly = 1
Compounded semiannually (6 month basis) = 2
Compounded quarterly (4 month basis) = 4
Compounded monthly = 12
Compounded daily = 365

To make navigation on this page easier, select the topic you are interested in learning more about:
- Compound Interest Formula

- Sample Problem

- Video Tutorial for Compounding & Simple Interest

Video Tutorial

The following is a really good explanation of compounding interest and simple interest

Compound Interest Formula

The formula to calculate compound interest (when finding A) is:

A = P(1 + r/n)nt


  • A = Amount of investment after interest has been compounded
  • P = Principal amount (initial investment)
  • r = Annual interest rate
  • n = Number of times the interest is compounded per year
  • t = Number of years (time)

Quick Reference

Interesting Epiphany
February 19, 2014

Interest IS... Interesting!

I am working on this article!

The Sandbox for Solving Problems

Sample Compound Interest Problem

Jayden has $5,000 to invest. If he deposits the money in a savings account, the bank will pay him 4.7% interest compounded quarterly. How much will he have if he keeps the money in the savings account for 5 years.?

Find A using the formula. First determine your variables:
- P = $5,000
- r = 4.7%
- n = Quarterly (it will compound 4 times a year)
- t = 5
The formula will look like the following:

A = $5,000 (1 + .047/4)4 * 5

A = $6315.89

Jayden will have $6315.89 if he invests his money for 5 years based on the interest compounding!


Sample Problem

Gathering the Facts

Chase started an office organizing business and has been working all summer. He has saved $4370 and isn't sure if he should put his money in a CD that guarantees 3.9% compounded monthly for a five year term, or if he should put it in a savings account that will accrue interest at 4% semi-annually. While the savings account gives him more flexibility to use the money if needed, he is curious to see how much more he will have if he puts his money in the CD.

By using the compound interest formula, he finds the following:
After the five year period in the CD, he will have $5309.23.
After the five year period in the savings account, he will have $5327.01
Even though the CD compounds monthly, he actually stands to earn more from the savings account earning 4% compounding semi-annually.