Enter your goal, savings, deadline, and APY to see how much to save each month.
Table of contents
How to use our Savings Goal Calculator
- Enter your Savings goal ($), or the total amount you want by the deadline.
- Enter Saved already ($) and Time to save (months) using whole months.
- Enter Expected APY (%); use 0 if you do not want interest included.
- Open Advanced options only if you want to change When you add savings or compare What you can save monthly ($) with the target.
- Check that Save this much each month feels possible, then use Goal status and any Gap or surplus at the deadline before changing the goal or deadline.
Definitions
Savings goal ($): The total amount you want saved by the end of the deadline.
Saved already ($): Money already set aside for this goal before any new monthly deposits.
Time to save (months): The number of whole months from now until the deadline.
Expected APY (%): Annual percentage yield. It is the yearly return after compounding is included.
When you add savings: The timing of each monthly deposit. Start-of-month deposits earn one extra month of interest compared with end-of-month deposits.
What you can save monthly ($): An optional amount used to test your current budget against the goal.
Gap or surplus at the deadline: The projected balance minus the savings goal. Negative means short, and positive means ahead.
Common mistakes and quick fixes
Mistake: Typing a range like 8000-10000 in Savings goal ($) .
Fix: Enter one target amount, such as 10000.
Mistake: Leaving Expected APY (%) blank because you do not know the rate.
Fix: Enter 0 if you want a no-interest plan, or enter the APY your savings account expects to pay.
Mistake: Using years in Time to save (months) , such as 2 instead of 24.
Fix: Convert the deadline to whole months before calculating.
Mistake: Choosing When you add savings as start of month when you actually save after each paycheck at the end of the month.
Fix: Use end of each month unless your deposit is made before that month earns interest.
Mistake: Treating Same pace per week as a separate weekly interest plan.
Fix: Use it as a budget shortcut only; the calculator still uses monthly deposits.
Mistake: Reading a negative Gap or surplus at the deadline as extra money.
Fix: Negative means the plan is short by that amount; positive means the plan is ahead.
Limitations & Key Assumptions / Boundary Conditions
- The calculator treats APY as a steady yearly rate for the whole saving period. Real savings rates can change.
- It converts APY to an equivalent monthly rate and assumes monthly compounding for the goal math.
- Regular deposits are treated as the same amount every month. Irregular deposits, skipped months, and one-time bonuses are not modeled.
- Same pace per week and Same pace every 2 weeks are budget equivalents, not weekly or every-2-weeks compounding schedules.
- Taxes, account fees, withdrawal limits, early withdrawal penalties, and bank posting delays are not included.
- Very negative or extremely high APY values can be unrealistic, so the calculator blocks rates that would break the math.
Methodology
How the monthly saving is found
The calculator first turns Expected APY (%) into a decimal yearly rate, then into an equivalent monthly rate.
apy_decimal = Expected APY (%) / 100
monthly_rate = (1 + apy_decimal)^(1 / 12) - 1
Next it grows Saved already ($) to the deadline.
future_current = Saved already ($) * (1 + monthly_rate)^Time to save (months)
It then finds the future value factor for equal monthly deposits.
if monthly_rate = 0: factor = Time to save (months)
if monthly_rate is not 0: factor = ((1 + monthly_rate)^Time to save (months) - 1) / monthly_rate
If When you add savings is start of month, the factor is multiplied by 1 + monthly_rate because each deposit has one extra month to grow.
raw_required = (Savings goal ($) - future_current) / factor
Save this much each month = max(0, raw_required)
Budget equivalents and interest
The weekly and every-2-weeks amounts are planning shortcuts based on 12 months, 52 weeks, and 26 every-2-weeks periods per year.
Same pace per week = Save this much each month * 12 / 52
Same pace every 2 weeks = Save this much each month * 12 / 26
Money you add yourself = Save this much each month * Time to save (months)
Estimated interest earned = Savings goal ($) - Saved already ($) - Money you add yourself
Optional budget check
When What you can save monthly ($) is entered, the calculator uses that amount instead of the required monthly amount to project the finish balance.
Projected balance with your monthly amount = future_current + What you can save monthly ($) * factor
Gap or surplus at the deadline = Projected balance with your monthly amount - Savings goal ($)
Mini example
For a $10,000 goal, $1,000 saved already, 24 months, 4% APY, and deposits at the end of each month, the monthly rate is about 0.3274%. The required monthly saving is about $357.80. That is about $82.57 per week or $165.14 every 2 weeks. Over 24 months, the new deposits total about $8,587.21, so about $412.79 of the goal is covered by estimated interest.