How to Calculate Savings Goals
Last updated: June 2026
The three levers
Any savings goal is a balance of three things: the monthly contribution, the time you have, and the return your balance earns. Fix any two and the third is determined. Want the goal sooner? Contribute more or earn more. Can't contribute more? Give it more time.
The simple version
Ignoring interest, the monthly amount is just the target divided by the number of months. For $15,000 in three years: 15,000 ÷ 36 = about $417/month. That's the floor — interest only makes it easier.
Adding interest
When your balance earns a return, your contributions are topped up by interest, so you need to save a little less. The future value of regular contributions is:
FV = PMT × [((1 + r)ⁿ − 1) ÷ r]
where PMT is the monthly contribution, r is the monthly return, and n is the number of months. Rearranging it solves for the contribution you need.
A worked example
Goal of $20,000, saving at 4% annual:
- Without interest: 20,000 ÷ 40 months = $500/month.
- With 4% interest, the same $500/month reaches the goal in about 37 months — interest contributes roughly $1,500.
On short goals the interest effect is small; on multi-year goals it becomes significant, which is why long-term savers should account for it.
Practical tips
- An initial lump sum plus monthly contributions reaches a goal faster than contributions alone.
- Automate the transfer so saving happens before spending.
- For goals years away, inflate the target — what you need will cost more later.
Use the calculator
Put these ideas to work with the Savings Goal Calculator. You can also browse all MoneyCalcKit calculators or read the calculator methodology for formulas and assumptions.
Frequently asked questions
How do I calculate a monthly savings amount?
Divide the target by the number of months for a simple figure. To account for interest, use the future-value-of-contributions formula, which lets you save slightly less.
Does interest really help on a savings goal?
On short goals the effect is small, but on multi-year goals compounding can meaningfully reduce how much you need to contribute.
Should I adjust my goal for inflation?
For goals several years out, yes — the cost will rise, so inflate the target to preserve purchasing power.