How is this different from an emergency fund?

A sinking fund is for a cost you can reasonably anticipate. An emergency fund is for genuine shocks and uncertainty.

What if I cannot afford the monthly total?

Use the result to prioritise. Reduce or delay lower-priority targets, look for a cheaper version, or start earlier. Do not silently fund the gap with expensive credit.

Should each cost have its own bank account?

Not necessarily. Separate pots can help organisation, but the important part is that the money is clearly allocated and not double-counted.

Budgeting

Sinking Fund Planner

A sinking fund is for a cost you can reasonably see coming, even if you do not know the exact final amount. The planner turns multiple targets and dates into one monthly funding requirement.

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Your estimate

Use the result as a planning guide and change inputs to test the assumptions that matter most.

How this calculator works

For each future cost, the calculator subtracts what you have already saved from the target and divides the remaining gap by the months available. The monthly requirements are then added together.

How to use it

Add each known future cost separately.
Use a realistic target and months until payment.
Add any money already ring-fenced for that cost.
Review the combined monthly requirement.
If the total is unaffordable, change the target, timing or priority rather than pretending the gap does not exist.

Assumptions and limitations

No interest is added to sinking funds and targets are assumed to be paid on the entered deadline. Actual renewal prices and repair costs can change.