Flat rate vs effective rate: what you're really paying

Walk into any Malaysian bank and the personal loan poster says something like '3.88% p.a.'. Take a housing loan brochure from the same bank and the number quoted works completely differently. Same word — 'interest' — two different mathematics. Here's the difference, with real numbers.

Flat rate: interest on the full amount, every year

Malaysian personal loans are traditionally quoted at a flat rate. Interest is charged on your original loan amount for the entire tenure, regardless of how much you've already repaid.

Example: borrow RM30,000 over 60 months at 3.88% flat. Interest = RM30,000 × 3.88% × 5 years = RM5,820. Total repayment = RM35,820, or RM597 a month. Simple, predictable — but notice you're paying interest on RM30,000 even in month 59, when you only owe a fraction of that.

Effective rate: interest on what you still owe

The effective rate (also called the reducing-balance rate) charges interest only on your outstanding balance, which shrinks with every payment. Housing loans and credit cards work this way.

The rule of thumb every Malaysian borrower should memorise: a flat rate is roughly equivalent to an effective rate of 1.8 to 1.9 times higher. So 3.88% flat behaves like roughly 7.3% effective. That's not a trick — it's just arithmetic — but it means you can't compare a 3.88% flat personal loan against a 4.5% effective mortgage refinance directly.

How to compare any two loans fairly

• Convert everything to total cost: total repayment minus amount borrowed.
• Ask every lender for the total interest in ringgit over your intended tenure — they must tell you.
• Watch for add-ons that change the real cost: processing fees, compulsory insurance, stamp duty (0.5% of the loan amount, standard in Malaysia).
• If you plan to settle early, ask how the rebate on unearned interest is calculated — with Prime Credit it's automatic and penalty-free.

The conversion table worth memorising

For a typical 5-year tenure, a flat rate converts to roughly 1.8–1.9 times its number in effective terms. That gives you a mental table: 3.88% flat ≈ 7.3% effective. 5% flat ≈ 9.3% effective. 6% flat ≈ 11.1% effective. 8% flat ≈ 14.6% effective — suddenly not far from a credit card.

This is also why Bank Negara requires banks to disclose the Effective Interest Rate alongside any flat rate in their product disclosure sheets. If a lender quotes you a flat rate and can't or won't tell you the effective equivalent, that itself is information.

When flat actually works in your favour

• Budget certainty: a flat-rate instalment never moves for the whole tenure — no repricing shocks when OPR changes, unlike floating-rate facilities.
• Early settlement with rebate: because unearned interest is refunded when you settle early (see our Rule of 78 guide), a flat loan you finish ahead of schedule costs meaningfully less than its headline suggests.
• Short tenures: over 12–24 months, the flat-vs-effective gap is small in ringgit terms, and the simplicity is worth it.

Five questions to ask before signing anything

• What is the total repayment in ringgit for my amount and tenure? (Forces every convention into one comparable number.)
• Is the rate flat or effective, and what is the other equivalent?
• What fees sit outside the rate — processing, stamp duty, compulsory insurance?
• If I settle early, how is my rebate calculated, and is there a penalty?
• What happens to the rate if I'm late — and does one late month reprice the whole loan?

Our calculator shows both views — flip the toggle between flat and effective to see exactly what the same loan costs under each convention before you commit.