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Two rates, two meanings, one comparison.

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A 4.8% flat facility and a 6% reducing-balance loan sit side by side in a comparison table looking like the cheaper one is obvious. It isn't. One conversion puts both in the same unit — and often reverses the answer.

The comparison nobody makes correctly

Malaysian lenders quote two different, incompatible things and call both a rate.

Flat rate — the one in the big font

  • Profit or interest computed on the original principal
  • Charged the same every month, for the whole tenure
  • Standard for hire purchase, and for Islamic sale-based financing
  • Understates the real cost by roughly half, every time

Reducing-balance rate (APR) — the one to compare on

  • Interest computed on what's still outstanding
  • The monthly charge shrinks as you pay down
  • Standard for credit cards, overdrafts, most home loans
  • The unit both offers have to be in before you can rank them

They are not comparable. Putting them in the same table without converting is the financial equivalent of comparing kilometres to miles because both are distance.

The conversion

eff ≈ flat × 2N/(N+1)

Flat to effective annual rate, where N is the tenure in months

Accurate to within a fraction of a percent across normal tenures. Good enough to make the decision with.

Why roughly double? Because on a flat-rate facility you're charged as though you still owe the full principal for the entire tenure — but by the halfway point you've repaid about half of it. You are paying for money you no longer have.

Worked through:

  1. 1

    Start with the flat rate and the tenure

    RM 20,000 over 60 months at 4.8% flat. Total profit is 20,000 × 4.8% × 5 years = RM 4,800. Total payable RM 24,800, instalment RM 413.33.

  2. 2

    Apply the conversion

    4.8% × (2 × 60) / (60 + 1) = 4.8% × 1.967 = 9.44% effective. That is the number to compare against a conventional APR.

  3. 3

    Now put the alternative next to it

    A conventional personal loan at 6% reducing balance over the same term costs about RM 3,200 in interest. The 4.8% facility costs RM 4,800. The "cheaper" rate is RM 1,600 more expensive.

  4. 4

    Sanity-check with total ringgit paid

    Rates can be argued about; total payable can't. RM 24,800 versus RM 23,200. If the two numbers disagree with your rate comparison, trust the ringgit.

  5. 5

    Then add the fees that sit outside the rate

    Processing fees, stamp duty, lock-in and early-settlement charges. On short tenures these routinely outweigh the rate difference entirely.

Where the shorter tenure trap bites

The conversion factor depends on tenure, and it's harshest where you'd least expect.

1.83× to 1.99×

Flat-to-effective multiplier from 12 months to 120 months

Short tenures aren't safe from this — a 12-month flat facility still costs ~1.85× its headline rate.

A 12-month facility at 5% flat carries a multiplier of 24/13 = 1.85, so it's really about 9.23% effective — it feels short and cheap, and it isn't cheap. An 84-month facility at the same 5% flat gets a slightly worse multiplier of 168/85 = 1.98, landing near 9.88% effective, on far more ringgit.

The multiplier converges towards 2 and never falls much below 1.8. There is no tenure at which a flat rate quietly becomes an honest rate.

What this means for Islamic financing specifically

Sale-based Islamic contracts — Murabahah, Tawarruq, BBA, AITAB — are structurally flat-rate. The profit is fixed at signing, which is precisely what makes them Shariah-compliant: there is no charge accruing on outstanding money over time.

That structure has two consequences, and they pull in opposite directions:

Works against you

  • The quoted rate understates the cost by roughly half
  • Comparison tables place it beside reducing-balance rates unconverted
  • Marketing has no incentive to do the conversion for you

Works for you

  • Early settlement cancels unearned profit via ibra'
  • Acceleration saves real money, month for month
  • The total cost is knowable on day one — no rate-hike risk

That last point is worth more than it's usually credited. A conventional floating-rate facility repriced upward in an OPR cycle. A Tawarruq facility signed at RM 24,800 payable costs RM 24,800 regardless of what BNM does for the next five years. Certainty has value; it just isn't free, and the price of it is in the effective rate.

Doing it in Duitful

  1. 1

    Pick the Islamic debt type

    In the Debts tab, choose Islamic — available to every user, no setting to enable. Plenty of Malaysian borrowers hold these facilities regardless of faith.

  2. 2

    Enter the facility from your offer letter

    Financed amount, total profit, tenure. Duitful shows the effective rate live as you type — before you save the row, and before you sign anything.

  3. 3

    Let the payoff queue rank on effective rate

    A 4.8% flat facility queues at ~9.44%, correctly ahead of an 8% card and behind a 15% one. Ranking it on its quoted 4.8% — or on the 0% APR it technically has — would put it in the wrong place for years.

  4. 4

    Model the acceleration

    Add an extra monthly amount on the Home tab. The drop in total profit charged is the ibra' you'd realise. On the RM 20,000 example, an extra RM 413/month cuts the tenure from 60 months to 27 and the profit from RM 4,800 to RM 2,160.

Common questions

Is the 2N/(N+1) formula exact?

It's an approximation, accurate to within a few tenths of a percent across normal tenures. The exact figure requires solving for the internal rate of return on the payment schedule. For deciding between two offers, the approximation is more than good enough — and it's the difference between converting and not converting that matters, not the last decimal.

Why do lenders quote flat rates at all if they overstate cheapness?

Because they're genuinely simpler to compute and to explain, and for hire purchase the convention predates modern disclosure rules by decades. Malaysian lenders are required to disclose the effective rate, but the flat rate is what gets the large font. That's a marketing choice, not a legal breach.

Does this mean Islamic financing is more expensive than conventional?

Not inherently. It means the quoted rates aren't comparable as printed. Some Islamic facilities are cheaper on an effective basis than the conventional alternative, some aren't — you find out by converting both and comparing total ringgit payable. The structure doesn't decide the price; the pricing does.

What about the ceiling profit rate on Islamic variable-rate financing?

Some Islamic home financing uses a contracted ceiling rate with a lower effective rate applied in practice, so the disclosed ceiling can look alarming next to a conventional quote. Compare the effective rate actually being charged, and check what the bank may do within the ceiling.

Should I refinance a flat-rate facility into a reducing-balance one?

Sometimes — but run the numbers on the settlement figure after ibra', not the statement balance, and include the lock-in fee and the new facility's processing costs. Refinancing that looks obviously good on the statement balance often stops looking good on the settlement figure.

One rule to carry away

Never compare two financing offers until both rates are in the same unit. Convert the flat rate, add the fees, then look at total ringgit payable — and if the rate comparison and the ringgit comparison disagree, the ringgit is right.

It takes about ninety seconds. It routinely reverses the answer.

Compare before you commit

Duitful converts flat-rate Islamic facilities to an effective rate and queues them correctly against conventional debt. Free, on your device, no account.

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