Sinking Fund Calculator
Turn a future bill or purchase into a monthly sinking-fund contribution.
Quick answer
Enter the target expense, current balance and number of months available. An optional APY shows how estimated interest may reduce the required monthly contribution.
Formula and calculation
The calculator grows current savings monthly, then solves the future-value-of-an-annuity formula for equal end-of-month contributions.
Worked example
To reach $6,000 in twelve months from $500 already saved, the required monthly amount is the remaining future-value gap divided across the available periods, adjusted for entered APY.
Limitations
The result assumes equal end-of-month deposits, a constant rate and no withdrawals, fees or taxes.
Source and methodology
Consumer Financial Protection Bureau saving resources. The source supports the general concept; ToolGemini uses only the values you enter and the formula described above.
Related tools
Money calculator hub · All calculators · Savings goal calculator
Frequently asked questions
What is a sinking fund?
It is money set aside gradually for a known future expense such as insurance, repairs, travel or annual fees.
Can I enter zero interest?
Yes. Enter zero for a transparent contribution-only plan.
Are deposits made at the start or end of each month?
This calculator assumes end-of-month deposits.