A flat rate loan calculator shows your monthly payment and total interest when interest is charged on the full original loan amount for the whole term. This is called a flat rate, and it is common for some car, personal, and dealer loans in the Gulf, Pakistan, and parts of Asia and Africa. The important thing to know is that a flat rate always costs more than the same number on a reducing balance loan. This tool helps you see the real cost and compare fairly, in more than 70 currencies. It is part of our interest calculators.
How to use the flat rate calculator
- Pick your country and currency, then set the flat interest method.
- Enter the loan amount you want to borrow.
- Enter the flat interest rate the lender quoted and the term in years.
- Read your results: the fixed monthly payment, the total interest, and the total amount payable.
What is a flat rate loan?
On a flat rate loan, interest is worked out once on the original amount you borrow and stays the same for the whole term, even as you pay the loan down. Your monthly payment is fixed and easy to predict, which is why some lenders like to quote it. The catch is that you keep paying interest on money you have already repaid, so it costs more than it looks.
How flat rate interest is calculated
The math is simple, which is part of the appeal:
Total interest = Loan amount × flat rate × years
Monthly payment = (Loan amount + total interest) / number of months
Worked example: Borrow 10,000 at an 8% flat rate for 5 years. Total interest is 10,000 x 0.08 x 5 = 4,000. You repay 14,000 in total, so the monthly payment is 14,000 / 60 = about 233. That 8% flat rate is close to about a 15.7% reducing balance rate, almost double.
Flat rate vs reducing balance: why flat costs more
On a reducing balance loan, interest is charged only on the balance you still owe, so it falls as you repay. On a flat rate loan it never falls. That is why the same headline number is far more expensive as a flat rate. The table shows the rough reducing balance rate that a flat rate is really equal to, on a 5-year loan.
| Flat rate | Roughly equal to (reducing balance) |
|---|---|
| 5% | about 9.8% |
| 8% | about 15.7% |
| 10% | about 19.7% |
| 12% | about 23.6% |
So if one lender offers 8% flat and another offers 12% reducing, the reducing offer is actually cheaper. To compare properly, run both with our reducing balance calculator and check the true yearly cost with the effective interest rate calculator.
Where flat rate loans are used
Flat rates are most common in car and personal loans from dealers and some lenders in the Gulf, Pakistan, India, and parts of Asia and Africa. You may also see them in consumer finance and some microfinance. Western banks usually quote an APR instead, which is closer to a reducing balance cost. Wherever you borrow, ask the lender clearly whether the rate is flat or reducing before you sign.
How to compare a flat rate offer fairly
- Ask which method the rate uses. A flat rate and a reducing rate with the same number are not the same cost.
- Convert it. Use the table above as a guide, or the effective rate calculator for the exact figure.
- Compare total interest, not just the monthly payment. A low monthly payment can still hide a high total cost.
- Check early repayment. On many flat rate loans, paying early does not reduce the interest you owe, so confirm the rules first.
Pros and cons of a flat rate loan
- Pros: simple to understand, fixed monthly payment, easy to budget.
- Cons: costs more than a reducing balance loan at the same rate, and early repayment often does not save interest.
Flat rate loans around the world
Rates and rules differ by country, so always check current terms with local lenders. See examples and currencies for your country:
Pakistan (PKR) · India (INR) · UAE (AED) · Saudi Arabia (SAR) · United Kingdom (GBP) · All countries
Frequently asked questions
What is a flat rate loan?
A flat rate loan charges interest on the full original amount for the whole term, even as you repay. The monthly payment is fixed and easy to predict, but it costs more than a reducing balance loan at the same rate.
How is flat rate interest calculated?
Total interest = loan amount x flat rate x years. The monthly payment is the loan amount plus total interest, divided by the number of months.
Is a flat rate cheaper than a reducing balance rate?
No. At the same number it is more expensive, because interest does not fall as you repay. A 5% flat rate is close to about 9.8% on a reducing balance basis over 5 years.
How do I convert a flat rate to a reducing balance rate?
As a rough guide, the reducing balance equivalent is close to double the flat rate on a 5-year loan. For an exact figure, use our effective interest rate calculator.
Where are flat rate loans used?
They are common in car, personal, and dealer loans in the Gulf, Pakistan, India, and parts of Asia and Africa, and in some consumer and microfinance. Western banks usually quote an APR instead.
Does paying early save interest on a flat rate loan?
Often not. On many flat rate loans the interest is fixed at the start, so early repayment may not reduce it. Check your loan agreement before you plan to pay early.
Built and maintained by Hira Fatima, BSc in Computer Science (BSCS)
Hira builds, tests, and maintains the calculators on loancalc.io and writes the guides that go with them.
How we calculate: Reducing balance uses the standard EMI formula; flat rate charges interest on the full original amount. | Last updated: June 2026
Disclaimer: This calculator gives estimates for planning only and is not financial advice. Your actual figures may differ due to fees, taxes, and lender policies. Confirm with your bank or lender before you borrow.