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Simple Interest

With simple interest only the principal earns, so the same amount accrues every year and you just multiply by the term.

Your numbers

Final amount

11,050,000

Interest

1,050,000

Formula

Interest = Principal × Annual rate ÷ 100 × Years

Most term deposits are simple; instalment products and loans behave closer to compound. Check the product terms.

What to enter

InputDefaultAccepted range
PrincipalThe money you put in — the base that earns interest.10,000,0000 and up
Annual rate (%)Interest quoted per year; the monthly rate is this over 12.3.50 and up
Years (yr)How many years the money stays put; compounding bites harder as this grows.30 and up

Step by step

FormulaInterest = Principal × Annual rate ÷ 100 × Years
With the default numbersInterest = 10,000,000 × 3.5 ÷ 100 × 3
AnswerFinal amount = 11,050,000

Quick reference table

Results when only Principal changes and everything else stays put.

PrincipalFinal amountInterest
5,000,0005,525,000525,000
7,500,0008,287,500787,500
10,000,00011,050,0001,050,000
15,000,00016,575,0001,575,000
20,000,00022,100,0002,100,000

What each result means

ResultAt default values
Final amountPrincipal plus interest — what you get at the end.11,050,000
InterestThe interest earned or owed over the period.1,050,000

Common mistakes

Most term deposits are simple; instalment products and loans behave closer to compound. Check the product terms.

Glossary

Principal
The money you put in — the base that earns interest.
Annual rate
Interest quoted per year; the monthly rate is this over 12.
Years
How many years the money stays put; compounding bites harder as this grows.
Final amount
Principal plus interest — what you get at the end.
Interest
The interest earned or owed over the period.

Frequently asked questions

Q. How is Simple Interest calculated?

Interest = Principal × Annual rate ÷ 100 × Years — With simple interest only the principal earns, so the same amount accrues every year and you just multiply by the term.

Q. Can you walk through an example?

With Principal 10,000,000, Annual rate 3.5%, Years 3yr, the answer is Final amount 11,050,000.

Q. What do I need to enter?

Enter Principal, Annual rate, Years. The result recalculates as you type, and an empty box counts as zero.

Q. How much does the answer move if I change a number?

Changing only Principal moves the answer to Principal 5,000,000 → Final amount 5,525,000 and Principal 20,000,000 → Final amount 22,100,000. The table below lays out five steps.

Q. How are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Q. Anything to watch out for?

Most term deposits are simple; instalment products and loans behave closer to compound. Check the product terms.

Related calculators

Tax rates and interest conventions differ by country and product — check your contract for real transactions.