Finance

Shop Simple Interest Total Calculator (20 Years)

Calculate simple interest and the total amount to repay. This shop version uses a 20-year planning term as its starting point.

This result means the Interest is the extra amount charged on the original principal over 20 years, and the Total is the principal plus that Interest, which is the full amount to repay at the end of the term.

Formula

Simple interest equals principal times rate times time, divided by 100.

How it works

Interest is charged only on the original principal, not on interest already added.

Worked example

Principal $10,000, annual rate 5 percent, term 20 years. Using the page formula, simple interest is $10,000 times 5 divided by 100 times 20, which is $10,000.00. The total to repay is $10,000 plus $10,000.00, which is $20,000.00. That is the calculator output for these defaults. Because time is an input on this page, each year page gives a genuinely different answer: interest grows by exactly $500 for every extra year, since 5 percent of $10,000 is $500 a year and simple interest never compounds. At 20 years the interest exactly equals the $10,000 borrowed, so the total to repay is double the original loan.

Who this term suits for a shop owner: a shop borrowing against a long lease fit-out or a freehold deposit loan, where the total of $20,000 is exactly double the amount borrowed and the owner should check that the premises will still suit the shop in 20 years.

FAQs

What is simple interest?
Simple interest is interest charged only on the original amount, not on accumulated interest.

Is this shop calculator exact?
No, it is an estimate for planning only, based on the numbers you enter.

Are these figures financial advice?
No, they are estimates for planning only, not financial advice. Check with a qualified adviser for decisions involving large sums.

Why does interest equal the principal at 20 years?
At $500 a year, 20 years gives $10,000 of interest, exactly the $10,000 borrowed, so the total to repay is $20,000, double the original loan. That crossing point is a useful check: beyond 20 years, interest costs more than the loan itself.

Is a 20-year shop loan the same as a premises mortgage?
Not exactly. A mortgage is usually repaid in instalments that reduce the balance, while this page charges simple interest on the full $10,000 for the whole term. Compare the lender's actual repayment schedule before treating the two as the same.

What if the rate is 4 percent over 20 years?
Using the same formula, interest becomes $10,000 times 4 divided by 100 times 20, which is $8,000, so the total becomes $18,000. One percentage point less saves $2,000 over 20 years.

Estimates only, not financial advice. Figures are approximate and do not include all fees, taxes, or changing rates unless stated.