Flat rate vs reducing rate: what the difference costs you

A flat rate charges interest on the original loan amount for the whole term, while a reducing rate charges interest only on the balance you still owe. The same quoted number therefore costs more as a flat rate: 5% flat over 48 months works out to about 9.24% reducing. Central Bank rules require UAE banks that advertise a flat rate to show the equivalent effective rate beside it.

Key takeaways

• A flat rate charges interest on the full original amount for the whole term; a reducing rate charges it only on the balance still owed.
• Over 48 months, a 5% flat rate equals a reducing rate of about 9.24% a year, so the same quoted number costs close to twice the interest.
• UAE banks that advertise a flat rate must show the equivalent effective rate next to it.
• Compare offers by the APR in the Key Facts Statement, which includes fees as well as interest or profit.
• If you settle early, you do not pay interest that has not yet been earned, but halfway through the term you still owe more than half the loan.

This guide works the same AED 100,000 loan out both ways, shows how to convert one rate into the other and explains why the Annual Percentage Rate (APR) is the figure to compare. Every rate on this page is an illustration, not a bank’s price.

How a flat rate works

A flat rate is applied to the full amount you borrowed, for every year of the loan, however much you have already repaid. The interest is fixed on day one and spread evenly across the instalments.

Two lines of arithmetic give you the whole loan:

• Total interest = loan amount × flat rate × number of years
• Monthly instalment = (loan amount + total interest) ÷ number of months

Take AED 50,000 at 4% flat over 2 years. The interest is AED 50,000 × 4% × 2 = AED 4,000. You repay AED 54,000 in 24 instalments of AED 2,250. In the last month you still pay interest calculated on the full AED 50,000, even though almost all of it has been repaid.

That is why a flat number looks low. It is not wrong, but it measures interest against money you no longer have. The Central Bank deals with this through disclosure: a flat quote must come with its reducing-balance equivalent.

Flat rate adverts

Effective rate shown

Any bank advertising a flat interest rate must show the equivalent effective (reducing-balance) rate next to it.

How a reducing rate works

A reducing rate, also called a reducing-balance or diminishing rate, charges interest each month only on what you still owe. Your instalment stays the same, but its split changes: the interest part is largest in the first month and shrinks every month after, while the principal part grows.

Each month the lender works out:

• Interest for the month = outstanding balance × annual rate ÷ 12
• Principal repaid = instalment minus that month’s interest
• New balance = old balance minus principal repaid

The fixed instalment that clears the loan exactly on time comes from the standard formula, where P is the loan amount, r the annual rate divided by 12 and n the number of months:

Instalment = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)

This is the method banks and finance companies licensed by the Central Bank must use. Article 6 of Regulation 29/2011 sets out the same monthly step: the interest is the balance at the start of the month times the annual rate divided by 12.

The Central Bank’s guidance on the Regulation adds that personal and car loan interest is calculated on the reducing balance with a 365-day year, based on average daily outstanding balances. The Consumer Protection Standards (clause 7.1.5.13) extend the reducing-balance method to loans and financing, overdrafts and unpaid credit card balances. Because banks count interest by the day, their figures for a given month can differ from the formula used on this page.

The same loan both ways: a worked example

On AED 100,000 over 48 months, a 5% flat rate costs AED 20,000 in interest, while a 5% reducing rate costs about AED 10,541. At the same quoted number, the flat loan costs close to twice as much.

The example uses 48 months because that is the longest term the Central Bank allows for a personal loan.

Maximum personal loan term

48 months

The repayment period of a personal loan must not exceed 48 months.

Worked example

AED 100,000 over 48 months at 5%, flat and reducing

The loan amount and the 5% rate are illustrations, not a bank’s offer.

1. Flat interest: AED 100,000 × 5% × 4 years = AED 20,000.
2. Flat instalment: (AED 100,000 + AED 20,000) ÷ 48 = AED 2,500.00.
3. Reducing instalment: the formula above with r = 5% ÷ 12 and n = 48 gives AED 2,302.93.
4. Reducing interest: the 48 instalments add up to AED 110,540.61, minus AED 100,000 borrowed = AED 10,540.61. The total is worked from the unrounded instalment, so it is 3 fils less than 48 × AED 2,302.93.
5. Difference: AED 2,500.00 minus AED 2,302.93 = AED 197.07 a month; over the term, AED 120,000.00 minus AED 110,540.61 = AED 9,459.39.

	5% flat	5% reducing
Monthly instalment	AED 2,500.00	AED 2,302.93
Total interest	AED 20,000.00	AED 10,540.61
Total repaid	AED 120,000.00	AED 110,540.61

At the same quoted 5%, the flat-rate loan costs AED 9,459.39 more in interest.

The flat loan’s AED 2,500 instalment matches a reducing rate of about 9.24% a year. When the loan is calculated on the reducing balance at that rate, the same AED 20,000 of interest is not spread evenly: most of it falls in the first two years. The table uses the monthly formula; a bank’s daily calculation gives slightly different figures.

Each year you pay AED 30,000 in instalments. In the first month, AED 770.15 of the AED 2,500 is interest; by the last month it is under AED 20. This pattern matters if you settle early, as shown further down.

Converting a flat rate to a reducing rate

To convert a flat rate, find the reducing rate that produces the same monthly instalment. There is no tidy exact formula for it: the rate is found by trial and adjustment, which a converter does instantly. A shortcut gets you close enough for a sanity check.

The exact method

1. Work out the flat instalment: (loan + loan × flat rate × years) ÷ months.
2. Find the reducing rate at which the instalment formula gives the same figure, by trying rates and narrowing the gap.

In the example, the flat instalment is AED 2,500, and the reducing rate that also gives AED 2,500 on AED 100,000 over 48 months is 9.24%. The loan amount does not change the answer, because both instalments rise and fall in proportion to it. Only the flat rate and the term matter:

As a rule of thumb, the reducing equivalent is a little under twice the flat rate. All the rates in the table are illustrations; the equivalents are calculated with the monthly formula.

A quick approximation

A common shortcut is:

Reducing rate ≈ flat rate × 2n ÷ (n + 1)

where n is the number of monthly instalments. For 5% flat over 48 months: 5% × 96 ÷ 49 = 9.80%. The exact answer is 9.24%, so the shortcut overstates it by just over half a point.

The shortcut assumes you repay the principal in equal slices. In a real reducing-balance loan the early instalments carry the most interest and repay the least principal, so the balance stays higher for longer and the true rate is lower than the shortcut says. Use it to check that a quote is in the right range, not to choose between two offers that are close.

Why the APR is the number to compare

The Annual Percentage Rate is the best single figure for comparing loans, because it includes fees as well as interest or profit. Central Bank standards require lenders to disclose it.

Annual Percentage Rate

APR disclosed

Lenders must disclose the Annual Percentage Rate (APR), which includes the total interest or profit payable and other fees compounded over a year.

A reducing rate puts flat and reducing quotes on the same footing, but it still leaves out fees. If a loan has an upfront charge, you receive less money for the same instalments, so the true cost of the money you actually get is higher than the reducing rate shows. The APR captures that. The Consumer Protection Standards say lenders must give you the expected APR so that you can compare credit products and institutions (Article 2, clause 2.1.3.2).

You find the APR in the Key Facts Statement, a short summary the lender must hand over before you commit.

Key Facts Statement

Before you sign

Lenders must give a Key Facts Statement before providing a financial product; it should be the first document in the sales process, and the consumer signs to acknowledge receiving it before signing the contract.

For a loan, the Key Facts Statement must show the expected annual interest or profit rate, the possible fees, the standard formula for working out the interest, and whether the rate is fixed, variable or a mix (clause 2.1.1.22). When a lender advertises an APR for a term loan, it must also show the total interest and fees over the term with an example (clause 2.3.3.2). More on what a lender has to tell you is in your disclosure rights.

Insurance is a separate decision. Central Bank guidance treats loans and insurance as separate products: you choose whether to pay for cover over the loan term or upfront, and the bank must explain this and get your agreement before charging you (Clarifications to Regulation 29/2011). When you compare offers, check whether each quote assumes insurance and whether its cost is included in the APR, so you compare like with like. Whatever the lender calls its fees, they are part of the APR.

Flat or reducing: which is better?

For the same quoted number, a reducing rate is always cheaper. But offers rarely quote the same number, so the label alone does not decide it: convert the flat quote to its reducing equivalent, then compare APRs.

A flat quote can win. Here are two illustrative offers for the same loan:

Worked example

Offer A at 4.5% flat against offer B at 8.5% reducing, AED 100,000 over 48 months

Both offers are illustrations, and fees are left out to isolate the rate.

1. Offer A interest: AED 100,000 × 4.5% × 4 years = AED 18,000. Instalment: AED 118,000 ÷ 48 = AED 2,458.33.
2. Offer A converted: the reducing rate that gives AED 2,458.33 over 48 months is about 8.36%.
3. Offer B instalment: the formula with r = 8.5% ÷ 12 and n = 48 gives AED 2,464.83.
4. Offer B interest: the 48 instalments add up to AED 118,311.86, so AED 18,311.86 of interest. As above, the total is worked from the unrounded instalment.

Offer A, the flat quote, is cheaper by AED 311.86 before fees, because 4.5% flat is about 8.36% reducing.

Fees can reverse that result, which is why the APR in each Key Facts Statement is the final check.

Settling early does not mean paying the rest of the flat interest. Central Bank standards limit what a lender can charge once you repay:

Early settlement and interest

No compounding

Lenders may not charge interest or profit on accrued interest on any consumer credit product, and may not charge future unearned interest after a loan is fully settled early; after a partial early settlement, interest must be adjusted to the remaining principal.

Go back to the year-by-year table. In that illustration, after 24 instalments of AED 2,500 you have AED 60,000 of instalments left, but your outstanding balance is AED 54,590.22. The other AED 5,409.78 is interest you have not yet incurred, so it falls away if you settle. Note the other side too: halfway through the term you owe more than half the loan, because the early instalments carried more interest and repaid less principal than the later ones. The lender may add an early settlement fee, within the Central Bank cap.

Personal loan early settlement fee cap

1%, max AED 10,000

For consumer (personal) loans, the fee table caps early settlement from other bank loans, final settlement from other sources such as end-of-service benefits, and partial payment at 1% each, with a maximum of AED 10,000.

The Key Facts Statement must include a worked example of the early settlement fee for the product (clause 2.1.3.8). The steps of an early settlement, from requesting the figure to the clearance letter, are a separate topic: see early settlement of a personal loan.

Where you meet flat rates in the UAE

A flat quote only works for a loan with fixed instalments, such as a personal loan, a car loan or Islamic financing where the cost is shown as a profit rate. Products whose balance moves up and down, such as credit cards and overdrafts, are charged on the outstanding balance, so there is no flat figure to convert.

Personal loans. The term can run to 48 months, and the 5% example above shows what a flat quote means at that length. The same comparison applies whether or not your salary is transferred to the lender; see personal loans without salary transfer for how those loans differ.

Car loans. Car loans can run longer than personal loans. At 60 months the reducing equivalent of a flat rate is slightly lower than at 48: 5% flat over 60 months is about 9.15% reducing.

Maximum car loan term

60 months

The maximum repayment period of a car loan is 60 months.

Down payments, eligibility and the other car loan rules are covered in the car loans guide; the rate comparison works the same way as on this page, and the car loan calculator takes a flat or a reducing rate.

Islamic financing. Central Bank guidance lets Islamic banks display rates using terminology permitted under Shariah, so Islamic financing may show a profit rate rather than an interest rate. The Consumer Protection Standards apply the APR and reducing-balance rules to interest and profit alike, so a flat profit rate converts in exactly the same way. How profit differs from interest in structure is explained in profit rates in Islamic finance.

Whatever the product, the steps are the same: convert any flat figure, read the APR in the Key Facts Statement, and compare the total you would repay. The flat to reducing rate converter and the loan payment calculator do the arithmetic for your own numbers.