Refinance Calculator (VND)
Refinancing means replacing your existing loan with a cheaper one — usually by paying off the current loan and taking out a new one at a lower rate, often with a different bank. A lower headline rate always looks like a win, but the real question is not whether the new rate is lower; it is whether the monthly saving pays back the upfront fees, and how many months that takes. In Vietnam those fees typically include an early-settlement charge on the old loan, notary and property re-valuation costs, and a disbursement fee on the new one. They are rarely trivial.
The arithmetic is straightforward. Every amortising loan has a fixed monthly payment given by P = B·r / (1 − (1+r)⁻ⁿ). Take a 1.500.000.000 VND balance with 10 years left: dropping the rate from 11% to 9% lowers the monthly payment from 20.662.502 VND to 19.001.366 VND — a saving of 1.661.136 VND a month. Divide the 15.000.000 VND of fees by that saving and you break even after about 10 months. Everything you save after that is money you keep.
The calculator above takes your balance, the old and new rates, the months remaining and your total fees, then returns the new payment, the monthly saving, the break-even point, and the total interest saved over the life of the loan. One caveat runs through all of it: the rates and fees in these examples are illustrative assumptions, not quotes. Vietnamese banks change their fee schedules and promotional rates constantly, and a headline "9%" is frequently a teaser that resets to a floating "base rate + margin" after the first one or two years. Pull the real numbers from your loan agreement before deciding.
How the calculator works out a refinance
1. The monthly payment on each loan
An amortising loan has a level monthly payment (an annuity):
P = B · r / (1 − (1 + r)⁻ⁿ)
| Symbol | Meaning |
|---|---|
| P | Combined principal-and-interest payment each month |
| B | Outstanding principal (1.500.000.000 VND) |
| r | Monthly rate = annual rate / 12 (11% → 0.917%/month) |
| n | Months remaining (120) |
Applied to both loans: the old loan at 11% costs 20.662.502 VND/month, the new one at 9% costs 19.001.366 VND/month. Monthly saving = 20.662.502 − 19.001.366 = 1.661.136 VND.
2. The break-even point
Break-even months = fees / monthly saving
This is how long the lower payment takes to recoup the fees you pay up front. In the example, 15.000.000 ÷ 1.661.136 ≈ 10 months (rounded up). If you expect to sell the property or repay the loan before that point, refinancing loses money — you never recover the fees.
3. Total interest saved over the life of the loan
Total interest on each loan = (monthly payment × months) − principal. The old loan pays 979.500.203 VND in interest, the new one 780.163.928 VND.
Lifetime saving = (old interest − new interest) − fees = 184.336.276 VND.
Why the new term matters
This comparison is only fair when the new term equals the time left on the old loan (both 120 months here). If you stretch the term when you refinance — say, a fresh 15 years on a loan with 10 years to run — the monthly payment falls further, but total interest can rise even at a lower rate, because you pay interest for more years. Always compare like-for-like terms to tell genuine saving from simply pushing debt further out.
What the model leaves out
The calculator assumes a fixed rate for the whole term on both loans, while most Vietnamese home loans carry a promotional fixed rate for a few years and then float at "base rate + margin". It also rolls every cost into a single fee figure and ignores loan insurance. Read the output as a comparison under a constant-rate assumption, not a guarantee.
Worked example: refinancing 1.500.000.000 VND from 11% to 9%
Illustrative assumptions: a 1.500.000.000 VND outstanding balance with 120 months (10 years) left, a constant rate on each loan, a new term also of 120 months, and total refinancing fees of 15.000.000 VND.
| Metric | Keep current loan (11%) | Refinance (9%) |
|---|---|---|
| Monthly payment | 20.662.502 | 19.001.366 |
| Total interest | 979.500.203 | 780.163.928 |
| Upfront fees | 0 | 15.000.000 |
Three takeaways.
- Immediate cash-flow relief. The payment drops from 20.662.502 to 19.001.366 VND — 1.661.136 VND lighter every month, which frees up roughly 19.933.628 VND in the first year.
- Break-even at 10 months. The 15.000.000 VND of fees divided by the 1.661.136 VND monthly saving means you recover the cost in about 10 months. Stay in the loan longer than that and refinancing comes out ahead.
- 184.336.276 VND saved over the loan. Total interest falls from 979.500.203 to 780.163.928 VND; after subtracting the 15.000.000 VND fee you keep 184.336.276 VND — provided the term and rate hold as assumed.
Enter your actual balance and the fee schedule the bank quotes you, and check whether the 9% is fixed for the full term or only a promotional rate for the first few years. FiMo also has mortgage and loan-comparison calculators if you want to lay several scenarios side by side.
Frequently asked questions
What is refinancing and is it worth it?
Refinancing replaces your current loan with a cheaper one, usually by settling the old loan and borrowing again at a lower rate. It is worth it when the monthly saving recovers the upfront fees within the time you keep the loan. Illustrative example: a 1.500.000.000 VND balance cut from 11% to 9% saves 1.661.136 VND/month and breaks even in 10 months. If you plan to sell or repay before then, it is not worth it.
How is the refinance break-even point calculated?
Break-even = total fees divided by the monthly saving, rounded up. It is the number of months the lower payment needs to recoup the fees you pay up front. Example: 15.000.000 VND of fees ÷ 1.661.136 VND saved per month ≈ 10 months. Keep the loan longer than that and refinancing pays off; repay or sell sooner and you lose the unrecovered portion of the fees.
What fees does refinancing a loan in Vietnam involve?
Usually four kinds: an early-settlement penalty on the old loan (often a percentage of the outstanding balance), notary and mortgage re-registration costs, a property re-valuation fee at the new bank, and a disbursement/appraisal fee on the new loan. Together they can run to tens of millions of dong. This calculator folds them into one "total fees" field (for example 15.000.000 VND) to compute the break-even. Ask the bank to itemise each charge before signing.
If the rate is lower, why can total interest still go up?
Because refinancing often comes bundled with a longer term. The monthly payment falls, but borrowing fresh over 15 years to replace a loan with 10 years left means you pay interest for more years, so lifetime interest can rise even at a lower rate. To compare fairly, set the new term equal to the months remaining on the old loan (120 months in the example). Done that way, total interest genuinely drops from 979.500.203 to 780.163.928 VND.
Is a promotional "9%" rate fixed for the whole loan?
Almost never. Most home loans in Vietnam fix the rate for the first 6 to 24 months, then float at a "reference/13-month savings rate + margin" (commonly +3% to +4%). So the 9% in the example is typically just a first-year teaser that can step up sharply afterwards. When weighing a refinance, don't look only at the promo rate — ask for the floating margin and re-run the calculator with the post-promo rate to stress-test the bad case.
How much do I save per month and over the life of the loan?
It depends on the balance, the rate gap and the fees. In the illustrative example (1.500.000.000 VND balance, 11% → 9%, 15.000.000 VND fees, same 120-month term) you save 1.661.136 VND/month and 184.336.276 VND over the life of the loan after fees. Enter your own figures in the calculator above to get the exact numbers for your situation.