How Much to Put in Sinking Funds Each Paycheck

By Deskline Digital · Published Oct 10, 2026 · All dollar amounts are hypothetical examples.

Once you've decided what your sinking funds are for (if not, start with our sinking funds list), the next questions are about numbers. How much should each fund have? How much goes in each paycheck? What if a fund is already behind? This guide covers the formula, works through examples on a biweekly schedule, and shows a simple way to track it all.

How much should a sinking fund have?

A sinking fund should reach the full cost of the expense by the date it's due. That gives every fund two numbers:

• Target: what the expense will cost. Use last year's bill, a quote, or your past spending, and round up a little.
• Due date: when you'll need the money. For costs with no fixed date (car repairs, home maintenance), use a yearly amount with a date 12 months out, then roll it forward each year.

Some funds are better treated as ongoing balances than one-time targets. For car repairs, many people set a ceiling (say, a hypothetical $1,500), contribute until they reach it, refill it after a repair, and stop contributing while it's full.

The formula

Per-paycheck amount = (target − already saved) ÷ paychecks left before the due date

That's it. The only tricky part is counting paychecks correctly, especially with biweekly pay, where the number of checks per month changes.

Worked example: three funds on a biweekly schedule

A hypothetical person is paid every other Friday. Today is payday, Friday, October 9, 2026. The next paydays are Oct 23, Nov 6, Nov 20, Dec 4, Dec 18, and so on every 14 days.

Fund 1: Holidays, $600 by December 20, nothing saved

Paychecks from today through Dec 20: Oct 9, Oct 23, Nov 6, Nov 20, Dec 4, Dec 18. That's 6 paychecks.

$600 ÷ 6 = $100 per paycheck.

Fund 2: Car insurance, $1,200 by April 15, 2027, $300 already saved

Remaining: $1,200 − $300 = $900. Paychecks from Oct 9 through Apr 9, 2027 (the last payday before Apr 15): 14 paychecks.

$900 ÷ 14 = $64.29 per paycheck.

Fund 3: Car repairs, $1,200 a year, ongoing

Treat it as a yearly cost. 26 paychecks a year, so $1,200 ÷ 26 = $46.15 per paycheck.

After December 18, the holiday fund is fully funded and its $100 drops out. The total falls to $110.44 until it's time to start saving for next year's holidays. This "lumpy" total is normal. Near-term funds cost more per check because they have fewer paychecks to spread over.

Monthly math vs counting paychecks

Many sinking fund calculators, including ours, work in months: the remaining amount ÷ months until due, then convert to a per-paycheck figure by multiplying by 12 and dividing by 26. That's quick and works well for funds due many months out. For a fund due soon, counting actual paydays (as above) can give a different number, since a short window can include more or fewer paychecks than the month count suggests.

A good habit: when the two methods disagree, use the larger number. Arriving at the due date with a little extra is better than arriving short.

What if you're behind?

Say the holiday fund should have been started in July and it's now mid-November with only $100 saved. From Nov 20, the paychecks left before Dec 20 are Nov 20 and Dec 4 and Dec 18: 3 paychecks. ($600 − $100) ÷ 3 = $166.67 per check. If that's too much, you have three honest options:

1. Lower the target. A $450 holiday is still a holiday, and a smaller target is better than a credit card balance in January.
2. Move the date, if the expense allows it (some purchases can wait).
3. Borrow from a fund with a later due date, and note it so you repay that fund over its remaining paychecks.

Then start next year's fund right after the holidays, with the full year to spread it over: $600 ÷ 26 = $23.08 per check.

How to fit sinking funds into your budget

Sinking funds are part of the savings side of your budget. In a 50/30/20 budget they come out of the 20%. Some people count fixed ones like car insurance as needs, since the bill is unavoidable. Either way, move the money on payday, before you start spending. Set up an automatic transfer if your bank allows it.

A 3-paycheck month is a natural time to top up funds that are behind. See 3-paycheck months.

Round up, and keep the math simple

$64.29 is an awkward amount to transfer every two weeks. Rounding each fund up to a clean figure ($65, $47, $100) makes transfers easier to remember and builds in a small cushion for price increases. In the example, rounding up turns $210.44 into $212 per check. That's an extra $1.56 per paycheck, and the fund finishes slightly early.

If you'd rather make one transfer, add up the rounded amounts and move the total to savings on payday. Then split it across the funds on paper. Once a year, ideally in January or when a big bill renews, recheck every target against the actual bills and reset the per-paycheck amounts.

How to track sinking funds in your budget

Most people keep all sinking funds in a single savings account and track each fund's share separately. A simple ledger:

Each fund column is a running balance. The rule is that the fund columns always add up to the account total. If they don't, something was spent and not recorded.

Prefer the bank to do it? Many banks offer labeled sub-savings or "buckets" inside one account. A spreadsheet, a notebook page or a printed tracker all work just as well. The best tracker is the one you'll actually update on payday.