Borrowing Power Calculator (VND)
If you are working in Vietnam and weighing up a property purchase, the most useful number to pin down first is not the price of any apartment — it is how much a bank will actually lend you. That ceiling is driven by two things you already know: your stable monthly income in VND and the debt repayments you already carry (a car loan, consumer credit, a credit-card balance).
The lever banks pull is the debt-to-income (DTI) ratio. They cap your total monthly debt service at a fixed share of income — an illustrative 40% here. Whatever is left after your existing repayments is the most you may pay toward a new loan each month. On 40.000.000 of monthly income, with 3.000.000 already going to debt and a 40% DTI cap, that affordable payment is 13.000.000 per month. Converted into loan principal at an illustrative 10%/year over 20 years, it implies a maximum loan of roughly 1.347.120.043.
From that loan, the tool estimates the property price you can reach. If a bank finances up to 70% of the property value and you cover the rest from savings, a 1.347.120.043 loan supports a home worth about 1.924.457.204 — leaving roughly 577.337.161 of equity for you to bring. One caveat that matters as a foreigner especially: every bank sets its own DTI ceiling, interest rate and loan-to-value policy, and mortgage eligibility rules for non-citizens differ. The figures here are illustrative assumptions to show the mechanics, not a quote from any lender.
How the calculator works
Step 1 — Affordable monthly payment
A bank caps your total debt service at the DTI ratio. What remains for a new loan is:
Affordable payment = Monthly income × DTI% − Existing debt payments
| Symbol | Meaning | Example value |
|---|---|---|
| Income | Stable monthly income | 40.000.000 |
| DTI | Debt-to-income cap (assumed) | 40% |
| Existing debt | Other monthly loan repayments | 3.000.000 |
| → Affordable payment | What is left for the new loan | 13.000.000 |
Step 2 — Convert to a maximum loan
That payment is discounted back to principal with the present-value-of-an-annuity formula:
Max loan = Affordable payment × (1 − (1 + r)^−n) / r
where r = annual rate ÷ 12 ÷ 100 is the monthly rate and n = term in months. With 13.000.000/month at an illustrative 10%/year over 240 months (20 years), the maximum loan is about 1.347.120.043.
Step 3 — Estimate the reachable property price
Property price ≈ Max loan ÷ loan-to-value ratio. Assuming a bank lends 70% of the property value: 1.347.120.043 ÷ 0.7 ≈ 1.924.457.204. The remaining 30% — around 577.337.161 — is the deposit you must fund yourself, before transfer taxes, notarisation and fit-out costs.
Why clearing old debt raises your ceiling
Every dong of existing repayment comes straight off the affordable payment. At a 40% DTI, each extra 1.000.000/month of existing debt cuts borrowing power by roughly 103.624.619 (illustrative 10%/year, 20 years). Paying down a high-rate consumer loan before applying often does more for approval odds than documenting extra income.
What the model leaves out
It assumes a fixed rate for the whole term (many Vietnamese home loans float after a promotional period), ignores appraisal fees, loan insurance and prepayment penalties, and uses a single illustrative DTI and loan-to-value ratio. Treat the result as an orientation estimate, not an approval.
Worked example: 40.000.000 income, 3.000.000/month of existing debt
Illustrative assumptions: a fixed 10%/year rate, a 20-year (240-month) term, and a bank that finances up to 70% of the property value. The table shows how borrowing power moves as the DTI ceiling changes:
| DTI cap | Affordable payment/month | Max loan | Estimated property price |
|---|---|---|---|
| 30% (conservative) | 9.000.000 | 932.621.568 | 1.332.316.526 |
| 40% (common) | 13.000.000 | 1.347.120.043 | 1.924.457.204 |
| 50% (stretched) | 17.000.000 | 1.761.618.518 | 2.516.597.883 |
Read across a row. At the common 40% cap you can pay up to 13.000.000/month once your existing 3.000.000 of debt is subtracted — about a 1.347.120.043 loan, reaching a 1.924.457.204 home. A more lenient bank allowing a 50% DTI lifts the ceiling to 1.761.618.518 — but you would then commit half of every paycheque to debt, which is far riskier if rates rise or income wobbles.
Notice the drag from existing debt. If the 3.000.000/month repayment were cleared before you apply, the affordable payment at 40% rises to exactly 16.000.000 and the loan ceiling grows by about 310.873.856. That is often the fastest way to expand borrowing power. Swap in your own figures, then cross-check with FiMo's DTI/LTI calculator and home affordability calculator for the full picture.
Frequently asked questions
How is borrowing power calculated?
In two steps. Step 1: multiply monthly income by the DTI cap, then subtract existing debt payments to get the affordable payment. Example: 40.000.000 × 40% − 3.000.000 = 13.000.000/month. Step 2: discount that payment back to principal with the present-value-of-an-annuity formula, here at 10%/year over 20 years → a maximum loan of about 1.347.120.043. These are illustrative assumptions; each bank sets its own DTI and rate.
What is DTI and what ratio do banks allow?
DTI (debt-to-income) is total monthly debt repayments divided by monthly income. Banks use it as a ceiling so you do not over-borrow. A common cap is around 40%, with conservative lenders nearer 30% and stretched policies up to 50%. On the same 40.000.000 income and 3.000.000 of debt: a 30% cap allows a 932.621.568 loan, while 50% allows 1.761.618.518. Every bank sets its own DTI policy — confirm directly.
How much deposit (equity) do I need to bring?
Whatever share of the price the bank will not finance. Assuming a 70% loan-to-value cap, you must fund at least the remaining 30% from your own money. A 1.924.457.204 home would need roughly 577.337.161 in cash — before transfer tax, notarisation, agent fees and fit-out. Loan-to-value limits vary by bank and property type, and can be stricter for foreign buyers, so treat this as an estimate.
How much does existing debt reduce my borrowing power?
Directly and materially. Each dong of monthly repayment comes straight off the payment the bank lets you make. At a 40% DTI, every extra 1.000.000/month of existing debt cuts your maximum loan by about 103.624.619 (illustrative 10%/year, 20 years). Clearing a high-rate consumer loan or credit-card balance before applying usually lifts your ceiling faster than trying to document extra income.
Does a longer loan term let me borrow more?
Yes — the same monthly payment supports a larger principal when spread over more months. The trade-off is more total interest paid over the life of the loan and a longer time in debt. This tool uses a 20-year term as the example; try other terms to see how the ceiling moves, then weigh the total interest cost with FiMo's mortgage payoff calculator before committing.
Are the interest rate and ratios here real bank figures?
No. The 10%/year rate, the 40% DTI and the 70% loan-to-value ratio are illustrative assumptions chosen to make the math easy to follow. Real Vietnamese mortgage rates, DTI caps and loan-to-value limits vary by bank, product and date, and rates often float after a promotional period. Enter the figures your bank actually quotes — the formulas behave identically at any values you supply.