Car loan calculator

The formula: amount financed equals car price minus down payment. Total interest equals amount financed times annual interest rate times number of years. The installment equals amount financed plus total interest, divided by the number of installments.

Roughly how much is the installment for a car at this price?

This table assumes a 20% down payment, a flat interest rate of 6% per year and 60 monthly installments, the same assumptions as the installment shown on car cards on this website. It is not a loan offer. Your actual interest rate may be higher or lower.

The flat rate is not the interest you really pay

Car hire-purchase loans in Thailand quote a flat rate, meaning interest is charged on the full original amount for the whole contract, even though you pay down the principal every month. The effective interest rate is therefore almost double the number you hear.

For example, from one financial institution's published rates in 2026, a flat rate of 5% per year over 48 installments is equivalent to an effective rate of about 9.2% per year.

The law caps hire-purchase interest as an effective rate: no more than 10% per year for new cars and no more than 15% per year for used cars. The contract must state the effective rate. Look for that number in the contract, not just the flat rate the sales staff tell you.

What are used car loan rates right now?

Based on several financial institutions' published rates in 2026, flat rates for used cars are around 4% to 8% per year, depending on the age of the car, the down payment and the borrower's history. Cars over ten years old sit at the top of that range, while new cars are around 3% to 5%.

• The longest term is about 84 installments, but each lender caps the car's age plus the loan term, so older cars cannot be financed for long.
• The loan amount is based on the lender's valuation, not the price you agreed with the seller. If the agreed price is above the valuation, the difference is extra down payment you have to pay.
• Ask the lender before you pay a deposit whether they will finance this model and year, how much they will lend, and at what rate.

Interest rates change all the time. These figures are a broad picture as of October 2026. Get quotes from at least two lenders. This website is not a lender, not a loan broker, and has no stake in any financial institution.

How much salary do you need to afford the payments?

Lenders look at all your debts combined compared with your income. The usual advice is that all debts together should not exceed about four tenths of your monthly income. But being approved by a finance company does not mean you can pay comfortably.

The rule we suggest using for yourself is that the car installment should be no more than about one quarter of your income, because the car also brings fuel, insurance, tax and repairs, which together often add several thousand baht more per month. Enter your income in the calculator above to see this ratio right away.

See the remaining costs in the yearly costs of owning a car and the questions to ask before signing in buying a used car on finance: what you need to know.

Three ways to cut the total interest

• Put more down. The amount financed shrinks, interest drops on every installment, and you often get a better rate too.
• Shorten the term. Try changing the number of installments in the calculator from 72 to 48 and watch the total interest line.
• Choose a younger car. Rates for younger cars are lower than for cars over ten years old. Sometimes a slightly more expensive but newer car costs less in total.