How this is calculated
- Your target fund. We add every essential expense you enter into a single
monthly figure, then multiply by your chosen months of coverage:
target = monthly essentials × months. Spend $3,000/month on essentials and want 6 months of runway, and your target is $18,000. Essentials should be your survival budget — rent/mortgage, food, utilities, insurance, minimum debt payments, and core costs like transport and phone — not discretionary spending you'd cut in a real emergency. - The gap.
gap = target − current savings, floored at zero. If you're already at or above your target, you're fully funded and the gap shows $0. - Months to reach the goal. Each month your balance earns interest and then
your contribution lands:
balance ← balance × (1 + monthly rate) + contribution. The monthly rate comes from your savings APY compounded monthly,monthly rate = (1 + APY)^(1/12) − 1, so the annual growth equals the APY you entered. We solve for the number of months where the balance first reaches your target and project the calendar funded date from today. With a 0% APY it's simply the gap divided by your monthly contribution. - Milestones & coverage. We also mark when your balance covers 1, 3, and
6 months of essentials — useful checkpoints on the way to the full goal. The coverage meter
shows how many months you're covered right now:
current savings ÷ monthly essentials.
What this doesn't model: changes to your expenses, income, or contributions over time; taxes on savings interest; variable or promotional APYs; or inflation eroding the target while you save. It's a smooth-curve planning estimate to size your fund and pace your saving — reality will be lumpier. The 3-to-6-month guideline (higher for variable income) is a widely used rule of thumb, not a guarantee.
Frequently asked questions
How many months of expenses should an emergency fund cover?
A common rule of thumb is three to six months of essential expenses. Lean toward the higher end — six to twelve months — if your income is variable or hard to replace: self-employed, single-income households, commission or gig work, one earner supporting dependents, or anyone in a field where a new job can take a long time to find. Lean toward the lower end if you have very stable dual incomes, strong job security, or other liquid backups. This is a planning heuristic, not a guarantee.
What should I count as an essential expense?
Count only what you must pay to keep the lights on if your income stopped: rent or mortgage, groceries, utilities, insurance premiums, and the minimum payments on your debts, plus core costs like transport, phone, and childcare. Leave out discretionary spending — dining out, subscriptions, travel, shopping — because in a real emergency you'd cut those first. A leaner essentials number gives you a realistic survival budget and a smaller, more reachable target.
Should I build an emergency fund or pay off debt first?
A widely used approach is to build a small starter fund of about one month of essentials (or a fixed amount like $1,000) first, so a surprise expense doesn't push you deeper into debt, then attack high-interest debt aggressively, and finally top the fund up to your full three-to-six-month target. High-interest debt often costs far more than a savings account earns, so a starter buffer plus fast payoff usually beats a full fund built alongside a lingering balance.
Where should I keep my emergency fund, and does the APY matter?
Keep it somewhere safe and liquid — an FDIC-insured high-yield savings or money-market account you can reach in a day or two, not invested in stocks where it could drop right when you need it. A higher APY helps a little: it shortens the time to your goal and offsets some inflation, but for a fund you may spend soon, easy access and safety matter far more than squeezing out the last fraction of a percent of yield.
Estimates only — not financial advice. This calculator is an educational planning tool, not financial, investment, or budgeting advice, and not a guarantee of any outcome. It doesn't account for changing expenses or income, taxes on interest, variable APYs, or inflation. Your right-sized emergency fund depends on your personal circumstances — verify your plan with a qualified financial professional. No liability is accepted for decisions made from these results.