Savings Goal Calculator
What to save each month or week to hit a target, or how long it will take
Last updated: October 2026
Your goal
36 months from now
How the calculation works
The APY is converted to a rate per deposit period. Your current savings are grown to the target date. The deposit is whatever amount, saved at the end of each period and earning the same rate, fills the remaining gap.
PMT = (Goal - S x (1 + i)n) x i / ((1 + i)n - 1)
In time mode the same equation is solved for n, the number of deposits, and rounded up.
Worked example
You want $20,000 for a home down payment in 36 months. You have $3,000 saved in an account paying 4.00% APY.
- The $3,000 grows to about $3,375 on its own.
- You need $435.89 a month: $15,692 of deposits, with interest covering the rest.
- With no interest at all you would need ($20,000 - $3,000) / 36 = $472.22 a month.
- If you can only spare $400 a month, the goal takes 39 months instead of 36.
Frequently Asked Questions
How much do I need to save each month to reach my goal?
Without interest, divide what is left to save by the number of months: $20,000 in 24 months is $833.33 a month. With interest the deposit is smaller because the money earns while it waits. To reach $20,000 in 36 months with $3,000 already saved at 4.00% APY, you need $435.89 a month.
What is the formula for a savings goal?
Grow what you already have to the target date: S x (1 + i)^n, where i is the rate per deposit period and n the number of deposits. The deposit that fills the gap is PMT = (Goal - S x (1 + i)^n) x i / ((1 + i)^n - 1). If the rate is 0, it is simply (Goal - S) / n.
How long will it take to reach my savings goal?
Switch to the time mode and enter what you can deposit. Starting from $3,000 and saving $400 a month at 4.00% APY, you reach $20,000 in 39 months. The calculator solves n = ln((Goal x i + PMT) / (S x i + PMT)) / ln(1 + i) and rounds up to the next whole deposit.
Should I save weekly or monthly?
It makes little difference to the total. Weekly saving puts money to work slightly sooner and can be easier to fit around a weekly paycheck. Pick the schedule that matches when you get paid, and automate the transfer so it happens before you can spend it.
Where should I keep money for a savings goal?
For goals within about five years, keep it somewhere it cannot fall in value: a high-yield savings account, a CD that matures before you need the money, or Treasury bills. Stocks can drop sharply in a year, which is a risk you cannot afford when the date is fixed.
What if I already have enough?
If your current savings will grow to the goal by the target date on interest alone, the required deposit is $0. The calculator says so and shows what your balance should reach.