Simple interest calculator

Simple interest calculator finds the principal amount, interest amount and interest rate using simple interest formula. This calculator can help you deal with all kinds of simple interest problems. The calculator prints an easy-to-follow, step-by-step explanation.

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Simple Interest Calculator

Find out the amount you'll receive after investing time.
help ↓↓ examples ↓↓ tutorial ↓↓

Principal:

Interest rate:

% per

Investment time:

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Simple Interest Calculator

In this calculator, you can select the value you want to find.
help ↓↓ examples ↓↓ tutorial ↓↓

I want to find

Input known variables:

Principal:

Interest rate:

% per

Investment time:

Interest:

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Examples

ex 1:

You put $1,000 into a bank account that pays 7% simple interest each year. You left the money in there for 3 years. Determine the interest earned and the total amount at the end of three years.

ex 2:

You deposit $12000 into a bank account with a monthly interest rate of 1.5%. You had the money in there for $210 days. Determine the amount of interest earned.

ex 3:

You put money into a bank account that pays 4% simple interest each year. After three years, you collected $72 in interest. How much was the deposit (principal)?

ex 4:

You put money into a bank account that pays 2% simple interest every six months. After 9 months, you received $15 in interest. How much was the principal?

ex 5:

You deposited $1000 into a bank account and received $50 in simple interest after three months. What was the interest rate?

ex 6:

You deposit $350 into a bank account with a monthly interest rate of 1.2%. Determine the length of time the money was in the bank if you received $9 in interest.

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Find more worked-out examples in our database of solved problems.

Simple interest

Simple interest is based only on the principal amount, unlike compound interest, where we use previously earned interest to calculate the next interest. For example if we invest \$100 for 3 years at an interest rate of 10% than we earn $10 each year. This calculator uses the following formula to solve simple interest problems: