How it works

This works the savings maths backwards: instead of asking what a monthly deposit grows into, it asks what monthly deposit is needed to reach a fixed target by a date.

Your existing balance is first grown to the deadline with FV = P × (1 + i)n. Whatever gap remains between that and your goal is filled by monthly deposits, solved with the annuity formula M = gap × i / ((1 + i)n − 1). Interest reduces how much you personally need to put in.

Worked example

To reach $50,000 in 5 years with $5,000 already saved and a 4% return, you'd need about $662 a month. Together with what you've already saved, roughly $44,700 comes from your own money and the remaining ~$5,300 from interest.

Frequently asked questions

What if I've already passed my goal?
If your current savings will grow past the target on their own, the monthly amount needed shows as $0.

Is the interest rate guaranteed?
No calculator can promise a return. Use a realistic, conservative rate for savings accounts and a higher (but riskier) one only if you're investing.

Does it store my numbers?
No. It runs fully in your browser with no accounts and no tracking.