Flat rate vs effective rate: how to compare loans without getting caught out

What a flat rate actually means

With a flat rate, interest is calculated once, at the start, on the full amount you borrow, for the whole period. That total is added to the amount borrowed and divided equally across your monthly instalments. Borrow RM10,000 at 12% flat for two years and the interest is simply RM10,000 × 12% × 2 = RM2,400. Your 24 instalments repay RM12,400 between them.

This method is used by licensed moneylenders, for hire-purchase car loans and for many personal loans from banks. It is simple to understand and easy to check with a calculator, which is a genuine advantage. The problem is what it leaves out.

Why the flat rate understates the cost

Every month you pay back part of the loan. After a year you owe only about half of the original amount — but with a flat rate you are still paying interest as if you owed all of it. On average across the loan you only have about half the money, yet you pay interest on the full amount the whole time.

That is why the true yearly cost is much higher than the headline number. For the kind of loans most people take — one to five years — the effective annual rate works out at roughly 1.7 to 1.8 times the flat rate. It isn't a hidden fee or a trick of one lender; it is simply what a flat rate means mathematically.

A quick way to sanity-check any flat-rate offer: multiply the flat rate by about 1.8 for loans of one to three years. A 10% flat loan costs roughly 18% a year in real terms, and an 18% flat loan roughly 31%. It's not exact, but it is close enough to tell you whether an offer is in the right range before you sit down with a calculator.

A worked example

Here is the RM10,000 loan at 12% flat over 24 months, calculated by the same code that runs our calculator. Look at the last line: the effective annual rate is well above 12%.

Nothing about this loan is unusual or unfair — it is priced well inside the legal limit. But if you compared it with a credit card at 15% a year on a reducing balance and assumed the loan was cheaper because 12 is less than 15, you would be wrong. The loan's effective rate is higher.

How the gap changes with the loan period

The longer the loan, the more total interest you pay, but the effective rate eases slightly because more of your instalments go to principal for longer. These figures are for RM10,000 at two flat rates:

Notice that a longer period does not make a loan cheaper in ringgit. Stretching RM10,000 at 12% from two years to five years lowers the instalment from about RM517 to about RM267 but more than doubles the interest, from RM2,400 to RM6,000. Choose the shortest period whose instalment you can comfortably afford.

How other kinds of credit are priced

Not all credit in Malaysia is quoted the same way, which is exactly why headline rates mislead. Some products charge interest on a reducing balance, where interest falls as you repay; others use a flat rate. The table shows the usual method for common types of borrowing.

Once every option is turned into an effective annual rate and a total in ringgit, you can line them up fairly. That is the only comparison that tells you which is genuinely cheaper for your situation.

Common myths

How to compare two offers properly

1. 1

   Use the same amount and period

   Ask each lender to quote for exactly the same loan amount and number of months. Different periods make any comparison meaningless.

2. 2

   Ask for the total repayable in ringgit

   This is the single most useful number. For the same amount and period, the lower total repayable is the cheaper loan.

3. 3

   Ask for the effective annual rate

   Licensed lenders should be able to tell you. If they can't or won't, put the figures into our calculator, which shows it for any flat-rate loan.

4. 4

   Add every fee

   Stamp duty is a fixed 0.5% with any licensed lender. Any processing, insurance or 'service' fee on top makes the loan more expensive — and an upfront fee is a red flag.

The legal limit, and what to do about rates above it

Under the Moneylenders Act 1951, a licensed moneylender may charge at most 18% a year flat on an unsecured loan, and 12% a year on a secured one. These are flat rates, so the effective rate on an 18% loan is around 29% to 32% — which is why it's important to borrow only what you need for as short a time as you can manage.

What to do next

• Try your own amount and period in our calculator — it shows both rates and the total cost
• Read our rates and fees page for every cost a licensed loan can carry
• When you're ready, send a quote request; you'll see the full cost again in writing before you sign anything