Free tool · Finance

Reserve Fund Calculator (Sinking Fund)

Free reserve fund (sinking fund) calculator for UK blocks. Add your planned major works and target years to see the recommended annual contribution and the cost per flat per month.

Recommended annual contribution

£9,433 / year

That is £98.26 per flat per month (£1,179 per year).

Total planned cost

£73,000

Current balance

£10,000

Shortfall

£63,000

Your balance currently covers 14% of all planned works.

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General information only — not legal, financial or professional advice. You are responsible for how you use these templates. Full disclaimer

A reserve fund (or sinking fund) spreads the cost of big, occasional jobs — roof, lift, external decoration — so leaseholders are not hit with a sudden special levy. This calculator lists your planned works, looks at how many years away each one is, and works out the contribution you need to collect each year to be ready in time.

How the calculation works

For each work item, the calculator divides the estimated cost by the number of years until you need it. Adding those figures together gives the recommended annual contribution. It then compares your total planned cost to the balance you already hold, so you can see your shortfall at a glance.

How to use it

  1. 1Enter your current reserve balance and the number of flats.
  2. 2Add each major work item with its estimated cost and how many years until it is due.
  3. 3Read the recommended annual contribution, and the cost per flat per month.
  4. 4Review the figures at every AGM and after each major project.

Get good estimates

The output is only as good as your cost estimates. Use a recent surveyor's report or contractor quotes, and revisit the plan when prices change. Pair this with our free reserve fund planner spreadsheet to keep a permanent record.

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Frequently asked questions

How much should a block hold in its reserve fund?+

Enough to cover known future major works as they fall due. A common approach is to estimate the cost and timing of each big job, then collect a yearly contribution that builds the balance in time. This calculator does that maths for you.

Is a reserve fund the same as a sinking fund?+

In UK leasehold blocks the terms are used interchangeably — both mean money set aside for future major works rather than day-to-day running costs.

Can leaseholders be forced to pay into a reserve fund?+

Only if the lease allows the landlord or RMC to collect reserve contributions. Most modern leases do, but check the wording before demanding contributions.

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