APR vs simple interest rate: the difference explained

By Samara Sweeney, Managing Director of Aurelius Capital ·

The short version

APR and simple interest are two different ways of pricing the same loan.

  • APR (annual percentage rate) charges interest on what you still owe. As you pay the loan down, the interest shrinks. Home loans work this way.
  • Simple interest charges a fixed percentage of the amount you borrowed, full stop. Most short-term business loans work this way.

Neither one is "the cheap one". They suit different jobs, and the trap is comparing a number from one system against a number from the other. Here's what each means and how to compare them properly.

What do APR and simple interest rate mean?

APR is the rate worked out on your remaining balance, expressed per year. Borrow $500K for a home at 6% and you'll pay interest on the balance that's outstanding each month. Over 30 years that's about $1.08M repaid in total. The interest comes to $579K, more than the amount you borrowed, simply because you held the money for so long.

Simple interest is easier to work out. It's a fixed percentage of the original amount. Borrow $10K at 11% simple interest for 6 months and the sum is: $10,000 x 0.11 x 0.5 = $550. That's the whole interest bill. You know the dollar cost before you sign.

Why the two numbers can't be compared directly

Time is the difference. APR spreads the cost over a year, so a short loan can look expensive in APR terms while costing very little in dollars. That $10K loan costs $550. Worked out the bank's way, it's an APR of about 18.6%. Same loan, same $550. One number sounds fine, the other sounds steep.

It cuts the other way too. The 6% home loan sounds cheap, and per year it is. But over 30 years it costs $579K. A high APR on a short loan can cost you less in real dollars than a low APR held for decades.

So when a lender quotes "11%" and another quotes "18.6%", they might be describing the same deal. You can't know until you put both in the same units.

Why business loans get quoted differently

Personal loans are covered by the National Credit Code, which forces lenders to advertise a comparison rate. One number, worked out the same way for every lender.

Business loans sit outside that law. There's no standard, so banks tend to quote APR-style rates and short-term lenders tend to quote simple interest. Both are legitimate. You just need to know which one you're reading.

The easy way to compare two business loans

Ignore the headline rates and ask each lender the same two questions:

  • What is the total amount I'll pay back, in dollars?
  • What do I owe if I pay it out early?

Total payback puts every loan in the same units, whatever system it was quoted in. And the early-payout answer matters because some short-term loans lock in the full interest amount on day one, while APR-style loans charge less if you finish early.

Fees sit on top of the rate and follow their own rules; that side is covered in the true cost of a business loan.

Using these terms to your advantage

If you need money for a short job, a simple interest quote tells you the dollar cost instantly, and the dollar cost is what matters. If you're borrowing for years, the annual rate is the number to negotiate, because time multiplies it.

And if you're holding two quotes in two different languages, that's a broker's job. We put business lending offers into the same units every day. The application form takes under a minute, and most enquiries get a response within four business hours.

Sources

Frequently asked questions.

APR (annual percentage rate) is the cost of a loan worked out on your remaining balance and expressed per year. You only pay interest on what you still owe, so the interest shrinks as you pay the loan down. Home loans and most bank business loans are priced this way.

Simple interest is a fixed percentage of the amount you originally borrowed. Borrow $10K at 11% simple interest for 6 months and the interest is $10,000 x 0.11 x 0.5 = $550. The dollar cost is known up front, which is why many short-term business lenders quote this way.

Neither is automatically cheaper; they're different ways of describing cost. A simple interest loan can carry a high APR but a small dollar cost because the term is short, while a low APR held for decades can cost more in dollars than the amount borrowed. Compare the total payback amount, not the headline rates.

Because APR spreads the cost over a full year, and a short loan packs its cost into a few months. A $10K loan costing $550 over 6 months works out to an APR of about 18.6%, even though $550 is a modest dollar cost. The APR isn't wrong, it's just answering a different question.

Ask every lender for the total amount you'll pay back in dollars over the term, and what you'd owe if you paid out early. Total payback puts an APR quote and a simple interest quote in the same units. A broker does this conversion across lenders before recommending one.

  • Business Lending
  • Commercial Finance

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