How the savings goal calculator works
Enter your goal, what you have saved already, the interest rate and how many years you have. The calculator grows your current savings at that rate, then works out the monthly deposit that makes up the rest, with interest compounding monthly.
The formula
Monthly deposit = (goal − current savings × (1+r)^n) × r / ((1+r)^n − 1), with r the monthly rate and n the number of months; monthly compounding.
Assumes a steady interest rate and a deposit at the end of each month. Real savings rates change.
Frequently asked questions
How much do I need to save each month?
Enter your goal, what you have now, the rate and the time frame; the calculator gives the monthly amount.
Does interest make a difference?
Yes — the calculator shows how much of your goal comes from interest rather than your own deposits.
What if I already have enough?
If your current savings will grow past the goal on their own, the monthly amount shows $0.
Results are estimates for planning, not financial advice. Last reviewed 2026-09-28.