Sinking Fund Calculator
Monthly amount needed to reach a lump sum.
Calculate the monthly contribution needed to accumulate a target lump sum by a set date at a given savings rate. Free and runs in your browser.
What this tool does
Enter target amount, years, and savings rate. The tool shows required monthly contribution.
Enter Values
Formula Used
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Calculations, display, or translation — let us know.
Disclaimer
Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.
Sinking funds are dedicated savings pots for specific future goals: new car in 4 years, roof replacement in 7, wedding in 2. 10,000 target in 3 years at 4% savings rate = 262/month approximately. Breaking lumpy goals into smooth monthly targets prevents the 'how will I afford this' panic when they arrive. Most well-run households have 3-5 sinking funds going simultaneously.
A worked example
Try the defaults: target amount of 10,000, years until needed of 3, annual savings rate of 4%. The tool returns 261.91. You can adjust any input and the result updates as you type — no submit button, no reload. That's the real power here: seeing how sensitive the output is to one or two assumptions.
What moves the number most
The result responds to Target Amount, Years Until Needed, and Annual Savings Rate. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.
The formula behind this
Required monthly contribution formula. Monthly compounding assumed. Everything the calculator does is shown in the formula box below, so you can check the math against your own spreadsheet if you want.
Why the number matters
Saving without a target is like driving without a destination — you'll make progress, but you won't know when you've arrived. This tool gives you a concrete figure to work toward, which is the first step in turning a vague intention into an actual plan.
What this doesn't capture
The calculation assumes a steady savings rate and a stable interest rate. Real saving journeys include emergencies, windfalls, and rate changes — especially in easy-access products. The figure is a direction of travel, not a guarantee.
Sinking fund contribution produces a monthly amount based on the inputs provided.
Inputs
This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.
Sources & Methodology
Methodology
Required monthly contribution formula. Monthly compounding assumed.
References
Frequently Asked Questions
How does this differ from a savings goal calculator?
Multiple sinking funds at once?
What savings rate to use?
Inflation adjustment?
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