How bank interest is calculated in Vietnam
Vietnamese banks quote rates per year. For loans, the way interest is applied to your balance matters as much as the rate itself.
1. Declining balance (most common)
- Monthly principal = Loan amount ÷ Number of months.
- Monthly interest = Remaining balance × (Annual rate ÷ 12).
- The payment is highest in month 1 and decreases as the balance goes down.
2. Flat rate
- Monthly interest = Original loan amount × (Annual rate ÷ 12), the same every month.
- Monthly payment = Principal + Interest, fixed for the whole term.
Consumer finance companies sometimes advertise a low flat rate; convert it to a declining-balance rate before comparing offers.
3. Savings interest
Interest = Deposit × Annual rate × (Months ÷ 12)
Term deposits in Vietnam pay simple interest at maturity. If you roll the deposit over, interest is added to the principal; use the compound interest calculator to see that effect.
4. Tips for borrowers
- Ask what happens after the fixed-rate period: the reference rate and the margin.
- Check the early repayment fee, often 1% to 3% of the amount repaid in the first years.
- Foreigners can borrow from some Vietnamese banks, usually with a work permit, a residence card and an employment contract covering the loan term.
Frequently asked questions
What is the declining balance method?
You repay the same amount of principal every month, and interest is charged only on the balance you still owe. Your payment is highest in the first month and falls a little every month. Most Vietnamese banks use this method for mortgages and personal loans.
What is a flat interest rate?
Interest is charged on the original loan amount for the whole term, so the monthly payment stays the same. For the same nominal rate, a flat rate costs considerably more than a declining balance rate.
What is a floating rate in Vietnam?
After an initial fixed period (often 6 to 24 months), Vietnamese banks usually reset the loan rate to a reference rate (such as the bank's 12-month deposit rate) plus a margin of about 3% to 4.5% per year.
Are online savings rates higher?
Yes. Most Vietnamese banks pay about 0.1% to 0.4% per year more for deposits opened online than at the branch counter.