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Sinking fund calculator

A sinking fund turns a future bill into a monthly amount. Enter what you need and when, and this tells you what to put aside.

$

The total amount you need.

$

Leave blank if you're starting from zero.

Set aside each month

Enter a target

One fund is easy to hold in your head. Six — car service, Christmas, insurance renewal, the vet — is where it falls apart, because each one has to survive alongside everything else you're spending. Alfie tracks them together against a real monthly budget.

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The idea

Most "unexpected" expenses are not unexpected. The car needs servicing every year. Insurance renews on the same date it renewed last year. Christmas happens in December. These are predictable costs that people choose, functionally, to be surprised by — and then absorb on a credit card.

A sinking fund converts a lump into a monthly number small enough to fit inside a budget. $1,200 of car maintenance is alarming. $100 a month is a line item.

Funds worth having

  • Car — servicing, tyres, registration, the repair you know is coming.
  • Insurance renewals — especially anything billed annually.
  • Christmas and gifts — start in January and December stops hurting.
  • Home repairs — appliances have a lifespan and it is shorter than you think.
  • Pets — routine care is predictable; the vet bill on top is what the emergency fund is for.

Why no interest calculation

This deliberately assumes no return. Sinking funds are short-term and usually held in cash, so the honest monthly figure is simply the amount remaining divided by the months available. Building in an assumed rate would make the target look easier than it is, and if the rate does not materialise you are short exactly when the bill arrives.

Related

  • Free monthly budget calculator
  • Zero-based budget calculator
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