Sinking Fund Calculator
List the costs you know are coming, such as car tax, the MOT, Christmas and birthdays, and see how much to set aside each month so the money is there when each one lands.
Your pots
Months away means how many pay days you have before the bill lands. Everything is worked out in your browser. Nothing you type is saved or sent anywhere.
Set aside this month
across your pots
Our Sinking Funds Tracker holds up to 15 pots with due dates and progress bars, and shows which costs land in which month, in Excel or Google Sheets.
See the Sinking Funds TrackerHow the sinking fund calculator works
List each cost you know is coming, how much it is, how many months away it is and anything you have already put aside. For each one the calculator works out a monthly amount, then adds them up to show what to set aside this month.
The sum behind it
For each pot: take the cost, subtract what you have already saved, and divide by the months you have left.
A worked example
| Pot | Cost | Months away | Already saved | Per month |
|---|---|---|---|---|
| Car tax | £200 | 5 | £0 | £40.00 |
| MOT and service | £300 | 7 | £0 | £42.86 |
| TV licence | £180 | 12 | £0 | £15.00 |
| Christmas | £500 | 3 | £100 | £133.33 |
| Birthdays | £240 | 12 | £0 | £20.00 |
| Total | £251.19 |
Christmas dominates because it is only 3 months away. Once each cost has been paid and its pot restarts with a full year to go, the same five pots need £118.33 a month in total. The calculator shows both figures, so you can see what the first year costs and what it settles down to.
The car tax and TV licence figures are the official UK prices as of October 2026. The others are examples, so swap in your own.
Not sure what to include?
Our list of 30 sinking fund ideas covers the common ones, with current prices for the costs that are set nationally. New to the idea? Start with how sinking funds work.
What the calculator doesn't do
It gives you this month's amount. It doesn't remember your pots, track top ups or show which months are expensive. Our Sinking Funds Tracker does all three, for up to 15 pots.
Frequently asked questions
What is a sinking fund?
A sinking fund is money you set aside a little at a time for a cost you know is coming but that doesn't happen every month, such as car tax, an MOT, Christmas or an annual insurance bill.
How do I work out a monthly sinking fund amount?
Take the cost, subtract anything you have already saved towards it, and divide by the number of months until it is due. A 200 bill due in 5 months with nothing saved needs 40 a month.
Why is the first year more expensive?
If a bill is due soon, you have fewer months to save for it, so the monthly amount is higher. Once it is paid and you start again with a full 12 months, the amount drops to the cost divided by 12.
How is a sinking fund different from an emergency fund?
A sinking fund is for costs you can see coming. An emergency fund is for things you can't predict, like a broken boiler or losing your job.
Does the calculator save my information?
No. Everything is worked out in your web browser and nothing you type is stored or sent anywhere.
Important: This calculator is a planning tool that works with the figures you enter. It is general information, not financial advice, and it does not take your personal circumstances into account. For free, impartial guidance, visit MoneyHelper.