Transum Software

Compound Interest Calculator

A customised online calculator for quickly finding the solutions to compound interest problems.

Compound Interest Calculator Online Exercise Exam-Style More Calculator Activities
Present Value (PV):
Number of years (n):
Interest rate (r):%
Compounding periods (k):%
Future Value (FV):
Interest (I):

Compound interest can be calculated by using the following formula to calculate the final amount or future value (FV)

$$FV = PV(1 + \frac{r}{100})^n $$

\(PV\) is the present value.

\(n\) is the number of years.

\(r\) is the rate of interest.

or by using the iterative function

$$x_{n+1} = x_n + \frac{x_n \times r}{100} $$

where \(x_0\) is the present value [See Calculator Workout Skill 16]

$$FV = PV(1 + \frac{r}{100k})^{kn} $$

\(PV\) is the present value.

\(n\) is the number of years.

\(r\) is the rate of interest.

\(k\) is the number of compounding periods per year.

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This web site contains over a thousand free mathematical activities for teachers and pupils. Click here to go to the main page which links to all of the resources available.

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Comment recorded on the 3 October 'Starter of the Day' page by Mrs Johnstone, 7Je:

"I think this is a brilliant website as all the students enjoy doing the puzzles and it is a brilliant way to start a lesson."

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"I think that having a starter of the day helps improve maths in general. My pupils say they love them!!!"

Featured Activity

Without Lifting

Without Lifting

Can you draw these diagrams without lifting your pencil from the paper? This is an interactive version of the traditional puzzle. Some diagrams are possible while others are not. What is the rule?


"Numeracy is a proficiency which is developed mainly in Mathematics but also in other subjects. It is more than an ability to do basic arithmetic. It involves developing confidence and competence with numbers and measures. It requires understanding of the number system, a repertoire of mathematical techniques, and an inclination and ability to solve quantitative or spatial problems in a range of contexts. Numeracy also demands understanding of the ways in which data are gathered by counting and measuring, and presented in graphs, diagrams, charts and tables."

Secondary National Strategy, Mathematics at key stage 3

Go Maths

Learning and understanding Mathematics, at every level, requires learner engagement. Mathematics is not a spectator sport. Sometimes traditional teaching fails to actively involve students. One way to address the problem is through the use of interactive activities and this web site provides many of those. The Go Maths main page links to more activities designed for students in upper Secondary/High school.


If you found this activity useful don't forget to record it in your scheme of work or learning management system. The short URL, ready to be copied and pasted, is as follows:

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