Sinking fund calculator
Enter what you're saving for, what you already have, and the date you need it. You'll get the exact amount to set aside each week, every two weeks, or each month — $1,200 for the holidays a year away is $100 a month, or $46.16 a paycheck.
How much should I put in a sinking fund each month?
Divide what you still need by the months left before the cost is due. A $900 car insurance premium due in 6 months needs $150 a month; $1,200 for the holidays 12 months out needs $100 a month. If some is already saved, subtract it first — $300 saved toward that $1,200 leaves $900, or $75 a month.
Round up to the next cent rather than down, so the last deposit doesn't leave you a few cents short. The calculator above does this for weekly, two-week and monthly deposits at once.
What are common sinking fund categories?
Anything you know is coming but don't pay every month: car insurance, car repairs and registration, holidays and gifts, annual subscriptions, travel, back-to-school costs, and home or pet care. Here's the monthly amount for each at example prices — spread out, even big costs get small.
| Fund | Goal | Time left | Per month |
|---|---|---|---|
| Car insurance | $900 | 6 months | $150 |
| Holidays & gifts | $1,200 | 12 months | $100 |
| Car repairs | $600 | 12 months | $50 |
| Annual subscriptions | $240 | 12 months | $20 |
| Summer trip | $2,700 | 9 months | $300 |
| Back to school | $400 | 4 months | $100 |
Example figures — swap in your own amounts and dates in the calculator.
Should I save weekly, every two weeks, or monthly?
Match it to your paycheck, so the money moves the day it arrives. Paid every two weeks? That's 26 deposits a year, so $1,200 becomes $46.16 per paycheck instead of $100 a month. Weekly pay makes it 52 deposits of $23.08.
With biweekly pay, two months a year usually bring a third paycheck — an easy month to get ahead. If your income changes week to week, the Irregular Income Planner works from your lowest likely month instead.
What if I fall behind on a sinking fund?
Recalculate from where you are: take what's actually saved off the goal and divide by the deposits left. $1,200 for the holidays with $300 saved and 6 months to go means $150 a month, up from $100. If that's too much, move the date or trim the goal instead of dropping the fund.
The Sinking Funds Tracker does this for you: when life happens, choose to keep the date or keep the amount, and it redoes the math across every fund.
What's the difference between a sinking fund and an emergency fund?
A sinking fund is for a cost you can see coming — you know roughly what and when, like a $900 insurance bill in March. An emergency fund is for the ones you can't: a lost job, a medical bill, a sudden repair. Sinking funds keep predictable costs from draining the emergency fund.
Good to know
Questions, answered.
How does the sinking fund calculator work out the amount?+
It subtracts what you've already saved from your goal, counts the weekly, two-week or monthly deposits left before your date, and divides. The result is rounded up to the next cent so your deposits always reach the goal — $1,200 over 26 paychecks is $46.16, not $46.15.
Is the calculator free, and does it save my numbers?+
It's free, with no sign-up. Everything is worked out in your browser — nothing you type is sent anywhere or saved.
How many sinking funds should I have?+
One for each cost you know is coming but don't pay every month — car insurance, car repairs, holidays and gifts, annual subscriptions, travel. Starting with two or three and adding more once the habit sticks keeps it manageable.
Where should I keep sinking fund money?+
Somewhere separate from everyday spending so it isn't spent by accident — a savings account, or one with separate buckets for each fund. A single account works too, as long as you know what each dollar is for.
What's the difference between this calculator and the Sinking Funds Tracker?+
The calculator handles one goal at a time and doesn't save anything. The Sinking Funds Tracker ($12, one payment) keeps every fund in one place on your device, tracks what you've put in, and recalculates when you fall behind or a date moves.
Is this financial advice?+
No. The calculator gives careful estimates to help you plan, and it isn't a substitute for advice from a professional.
Every fund, one screen
Keep all your sinking funds in one place.
The Sinking Funds Tracker holds every goal, shows the one number to save for each, and recalculates when a date moves. Private to your device, no account.
$12 · one payment, yours forever