Financial Runway Calculator (VND)
Financial runway is the number of months you can keep living off your savings if your main income stops — a layoff, a planned career break, a business pause, or the gap between two jobs. If you live and work in Vietnam, you think about this in Vietnamese dong: a cushion of savings in the hundreds of millions, monthly costs in the tens of millions. This calculator answers one precise question: if the salary stops next month, how long does my money last?
The core math is simple: runway in months = savings ÷ monthly expenses. With 150.000.000 VND saved and 20.000.000 VND/month of expenses (both illustrative inputs — replace them with your own), the runway is about 7.5 months, or 7 months. If you keep some income during the gap — freelance work, rental income, remote contracting — you only have to cover the shortfall, so the runway stretches: with 8.000.000 VND/month of ongoing income, the same savings last 12.5 months.
This is deliberately distinct from an emergency fund. An emergency-fund calculator tells you how much you should set aside (commonly 3–6 months of expenses) — it sizes a target. A runway calculator takes the money you actually have today and tells you how far it goes. One is the goal; the other is the reality check. Reach for this tool when you are planning a resignation, weighing a sabbatical, or pricing the risk of a job loss in a foreign country where you may have fewer fallback options than at home.
How the calculator computes runway
The core formula
Runway (months) = Savings ÷ Net monthly burn
where net monthly burn = monthly expenses − ongoing monthly income.
| Symbol | Meaning |
|---|---|
| Savings | Cash you can actually access now (deposits, liquid funds) |
| Monthly expenses | Your total cost of living per month |
| Ongoing income | Income you still receive after the main job stops |
| Net monthly burn | The shortfall you must draw from savings each month |
If ongoing income ≥ expenses, net burn is zero or negative — you are no longer drawing down savings, so the runway is effectively unlimited (the tool flags this rather than dividing by zero).
Years/months and the run-out point
The tool divides the month count by 12 to show a "X years Y months" view that is easier to picture, and it describes the run-out point as "in about N months" rather than a calendar date, because the date depends on when you start. The fractional last month is rounded down on the "safe months" card: the final partial month is only partly funded, so it should not be counted as a full safe month.
What the model leaves out
The calculation assumes level spending with no inflation and no shock costs (medical bills, a flight home, an urgent repair). It also ignores any interest earned on the savings you have not yet spent — over a horizon of a few months that interest is small, and ignoring it is the conservative choice. Treat the result as a base case: in practice, pad it and keep a buffer. If you want the inverse — "how much should I save to cover 6 months?" — use FiMo's emergency-fund calculator instead.
Worked example: 150.000.000 VND saved, 20.000.000 VND/month of expenses
Illustrative inputs: 150.000.000 VND of savings, no income during the break. The table shows how runway moves with your expense level — the single biggest lever you control:
| Monthly expenses | Runway | As years/months |
|---|---|---|
| 15.000.000 | 10.0 months | 0y 10m |
| 20.000.000 | 7.5 months | 0y 7m |
| 25.000.000 | 6.0 months | 0y 6m |
| 30.000.000 | 5.0 months | 0y 5m |
At 20.000.000 VND/month, 150.000.000 VND lasts 7.5 months. Trimming spending to 15.000.000 VND/month pushes the runway to 10.0 months — an extra 2.5 months without adding a single dong of savings. Conversely, spending 30.000.000 VND/month cuts the runway to just 5.0 months.
With partial income
Keep the same 150.000.000 VND saved and 20.000.000 VND/month of expenses, but assume you still earn 8.000.000 VND/month from freelance work during the gap. Net burn drops to 12.000.000 VND/month, so the runway stretches from 7.5 months to 12.5 months (about 12 full months). This is why many people take part-time work during a career change: it does not need to cover everything — just slowing the burn rate buys a meaningful amount of runway.
Frequently asked questions
What is financial runway?
It is the number of months you can live off your savings if your main income stops. The formula is savings ÷ monthly expenses. Illustrative example: 150.000.000 VND saved at 20.000.000 VND/month of expenses gives a runway of 7.5 months. It tells you how long you are "safe" before you need income again.
How long will 150 million VND in savings last?
It depends on your spending. With 150.000.000 VND and no income: 15.000.000 VND/month lasts 10.0 months; 20.000.000 VND/month lasts 7.5 months; 30.000.000 VND/month lasts only 5.0 months. Enter your real monthly expenses into the calculator for an accurate figure.
How is runway different from an emergency fund?
An emergency fund answers "how much should I set aside" — usually a target of 3–6 months of expenses. Runway takes the money you already have and tells you how long it lasts. One sizes a goal; the other is a reality check on your current position. To work out the savings target instead, use FiMo's emergency-fund calculator.
What if I still earn some income during the break?
You only cover the shortfall, so the runway is longer. The formula becomes savings ÷ (expenses − ongoing income). Example: 150.000.000 VND, 20.000.000 VND/month expenses, but 8.000.000 VND/month of freelance income → net burn of 12.000.000 VND/month, stretching the runway from 7.5 to 12.5 months.
How many months of runway should I have before quitting?
There is no fixed rule, but many people aim for at least 6 months for a break or job search, and more if the job market is tight or they are changing careers — especially relevant if you are working abroad with fewer fallbacks. Add a buffer for surprises. The tool shows where you stand today; choosing the safe level is up to you.
Does the calculator account for inflation or interest on savings?
No. It is a base case: it assumes level spending and ignores inflation, shock costs, and any interest your unspent savings earn (over a few months that interest is small, and ignoring it is the conservative choice). In practice, pad the result and keep a buffer for unexpected expenses.