Savings Goal & Runway Calculator
Two sides of the same question: how long until your savings reach a goal — and how long your savings would last if you lived off them.
Your numbers
Use your savings account APY, or an expected investment return.
Your result
Your numbers
Interest earned while you spend slows the decline — sometimes enough to last indefinitely.
Your result
Assumes steady monthly spending and a constant rate of return. Inflation would shorten the real runway, since future spending tends to rise.
How savings goals and runway work
For a goal, the calculator grows your balance month by month — adding your contribution and applying interest — until it crosses your target. The result splits the final amount into money you put in versus growth you earned, which is often the most motivating number on the page.
Each month: balance = balance × (1 + annual rate ÷ 12) + monthly contribution (goal mode) or − monthly spending (runway mode). Repeat until the goal is reached or the balance runs out.
For runway, there's a tipping point: if monthly interest on your balance is greater than your monthly spending, the balance never falls — it grows. At a 3% return, that takes about $1.12 million to cover $2,800/month; at lower balances, interest still stretches every dollar further than simple division suggests.
Frequently asked questions
How much should my emergency fund be?
The common guideline is 3–6 months of essential expenses — use the runway mode above with your bare-bones monthly spending to see what that means for you. Single-income households, freelancers, and anyone with variable income usually aim for the higher end.
What interest rate should I use for a savings account?
Use the APY on your actual account. High-yield savings accounts have recently paid around 4–5%, while traditional bank savings accounts often pay under 0.5% — on a $50,000 goal, that difference can change your timeline by months.
Why does the goal date move so much when I change the monthly amount?
Because contributions compound too. An extra $100/month doesn't just add $100 — every past contribution is also earning returns. Over a 10-year goal, an extra $100/month at 5% adds about $15,500 to the final balance, not $12,000.