Case 1
- Future expense amount
- 600
- Already earmarked for this expense
- 0
- Deposits remaining before the expense
- 6
100.00
- Remaining funding gap
- 600.00
- Total of planned deposits
- 600.00
- Nonzero deposits needed
- 6
- Final nonzero deposit (0 if funded)
- 100.00
Sinking Fund Calculator
Change any value to update the result.
100.00currency
Regular deposit until funded: 100.00 currencyRemaining funding gap: 600.00 ; Total of planned deposits: 600.00 ; Nonzero deposits needed: 6 ; Final nonzero deposit (0 if funded): 100.00
- Remaining funding gap
- 600.00
- Total of planned deposits
- 600.00
- Nonzero deposits needed
- 6
- Final nonzero deposit (0 if funded)
- 100.00
Personal inputs stay on this device. Sharing sends the calculator page without these values.
Examples
Subtract earmarked savings from the expense. Divide the gap across deposits before it is due, rounding up to a cent. The last nonzero deposit may be smaller; stop once funded. An already funded expense needs no deposits.
The numbers at a glance
Held fixed: Future expense amount 600.00 currency, Already earmarked for this expense 0.00 currency.
| Deposits remaining before the expense | Regular deposit until funded |
|---|---|
| 2 | 300.00 |
| 4 | 150.00 |
| 6Your value | 100.00 |
| 8 | 75.00 |
| 10 | 60.00 |
| 12 | 50.00 |
Worked examples
Case 2
- Future expense amount
- 840
- Already earmarked for this expense
- 0
- Deposits remaining before the expense
- 12
70.00
- Remaining funding gap
- 840.00
- Total of planned deposits
- 840.00
- Nonzero deposits needed
- 12
- Final nonzero deposit (0 if funded)
- 70.00
Case 3
- Future expense amount
- 100
- Already earmarked for this expense
- 0
- Deposits remaining before the expense
- 3
33.34
- Remaining funding gap
- 100.00
- Total of planned deposits
- 100.00
- Nonzero deposits needed
- 3
- Final nonzero deposit (0 if funded)
- 33.32
How it's calculated
gap = max(0, expense − saved); regular cents = ceil(gap cents / remaining deposits)
- StepEnter the expense and earmarked savings in one currency.Already earmarked for this expense=0currency
- StepCount the deposits you can make before the expense is due.Deposits remaining before the expense=6
- StepSave the regular amount until the final smaller deposit funds the gap.Future expense amount=600currency
- ResultStop once funded; later deposit slots require no payment.100.00currency
All deposits occur before the expense. No interest, inflation or currency conversion is included.
What this number means
This is a no-interest funding plan using deposits before an expense. YNAB's published insurance example divides 600 over six months into 100 each month. Enter your actual deposit count; it need not mean calendar months.
A synthetic 100 gap with three deposits needs 33.34, 33.34 and 33.32. Exact cents prevent overfunding. If rounding funds the expense early, later deposits are zero.
Use at most two decimals and subtract only money already earmarked for this expense. Interest, inflation, taxes and currency conversion are excluded. An estimated future cost or date can change; the result neither assesses affordability nor guarantees coverage.
Questions
What if savings already exceed the expense?
The funding gap and deposits are zero. The calculator does not reassign the excess savings.
Why can the last deposit be smaller?
The regular amount rounds up to a cent. The last payment covers only the remaining gap; later payments are zero.
Are deposits always monthly?
No. Enter the actual number of deposits before the expense; interest and calendar deadlines are not modeled.
Sources and last check
- YNAB: How to Save MoneyFormula / method
- YNAB: What is a Sinking Fund?Formula / method
- YNAB: Where Did My Money Go?Formula / method
Information, not financial advice.