What to set aside
Total per month
—
Per paycheck
—
Still to save
—
Combined target
—
Funds fully funded
—
Next one due
—
Each fund
| Fund | To go | Months | Per month | Saved |
|---|
Per month = (target − already saved) ÷ months left. No interest or returns are assumed, so the plan works with a plain savings pot or envelope.
This is an educational calculator only, not financial advice. It assumes level monthly saving and no interest earned. Numbers stay in your browser.
How a sinking fund works
A sinking fund is money you set aside, a little at a time, for a cost you already know is coming: a yearly insurance premium, new tires, school fees, gifts, a trip, or a repair. Instead of the bill landing on one month's budget, it is spread over the months before it is due, so nothing has to go on a card or be borrowed.
The math is one line. Take the target, subtract what you have already put aside, and divide by the months left. A 1,200 insurance premium due in 9 months with 300 already saved needs (1,200 − 300) ÷ 9 = 100 a month. The calculator does this for every fund and adds them up.
Per paycheck. If you are paid every two weeks, that is 26 paychecks a year, so a monthly total of 325 becomes 325 × 12 ÷ 26 = 150 per paycheck. Moving the money on payday makes it automatic.
If the total is too high, push a date out, lower a target, or start with the funds that are due first. A plan you can keep is better than a perfect one you abandon in March.
Common sinking funds
- Car: servicing, tires, registration, repairs
- Yearly bills: insurance premiums, memberships, software and subscriptions billed annually
- Home: repairs, appliances, furniture
- Family: gifts, celebrations, school costs, travel to see relatives
- Health: dental, glasses, other costs your cover does not pay
- Giving: charity or zakat you plan to give on a set date
Questions
What is a sinking fund?
A sinking fund is money you save in small regular amounts for a specific, expected expense, such as a yearly insurance premium, car repairs, or gifts. When the bill arrives the money is already there, so you do not need to borrow or squeeze one month's budget.
How do I calculate how much to put in a sinking fund each month?
Subtract what you have already saved from the target and divide by the number of months until you need the money. For example, 900 for car maintenance in 10 months with 150 saved is (900 - 150) / 10 = 75 a month.
What is the difference between a sinking fund and an emergency fund?
A sinking fund is for costs you can see coming. An emergency fund is for costs you cannot predict, like a job loss or an urgent repair. Most budgets use both: several sinking funds plus one emergency fund.
Should sinking funds be in one account or separate accounts?
Either works. Some people keep one savings account and track each fund in a spreadsheet; others open separate pots or envelopes. What matters is that you can see how much belongs to each goal.
Does this calculator include interest?
No. It assumes level monthly saving with no interest or investment returns, which keeps the plan simple and works with any savings pot, envelope, or account.
Are my numbers saved or sent anywhere?
No. The calculator runs entirely in your browser. Nothing you type is stored or sent to a server.
Keep your sinking funds in a spreadsheet
The Wellkept Couples & Paycheck Budget has a Sinking Funds sheet that works out the monthly amount for each goal (and each partner's part), a Paycheck Plan that assigns every bill and savings transfer to the paycheck that covers it, and a shared-bills log. Excel and Google Sheets, English and German. $19, files stay with you.
See the Couples & Paycheck Budgetor start with the free Monthly Budget Starter