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Sinking fund calculator

See what the society should set aside each year — and per flat — to be ready for a major repair.

Your society

Repair or sinking fund today. 0 if none.

The repair

Your engineer's or contractor's estimate.

Assumptions

Use 0 to be cautious.

Compare with the Model Bye-law minimum

Only for societies that adopted the Maharashtra Model Bye-laws (2014). Bye-law 13 sets minimum yearly contributions as a percentage of each flat's construction cost, as certified by the architect: 0.25% for the sinking fund (excluding land) and 0.75% for the repairs and maintenance fund.

Sinking fund estimate

Estimated future repair cost

Enter the number of flats, the repair cost and the expected year to see the plan.

A planning estimate from the assumptions you enter.

Good to know

How each number is calculated

  1. 1.

    Years to go. Expected repair year minus this year.

  2. 2.

    Estimated future repair cost. Today's cost × (1 + inflation)^years. With 6% inflation over 5 years, ₹50 lakh becomes about ₹66.9 lakh.

  3. 3.

    Reserve at the repair year. Today's reserve × (1 + interest)^years. With 0% interest it stays the same.

  4. 4.

    Shortfall. Future repair cost minus the reserve at the repair year (never below zero).

  5. 5.

    Yearly contribution. With no interest: shortfall ÷ years. With interest, the equal year-end contribution that grows to the shortfall: shortfall × r ÷ ((1 + r)^years − 1). Per flat = yearly contribution ÷ number of flats.

Important assumptions

  • This is an estimate for planning. It doesn't tell you what your society must keep in its sinking fund.
  • Inflation and interest are your assumptions. Construction costs can rise faster than general inflation — ask your structural engineer or architect for a realistic repair estimate.
  • Contributions are assumed to be equal every year and shared equally per flat. Your bye-laws may share them differently.
  • Where a society has adopted the Maharashtra Model Bye-laws (2014), bye-law 13(c) sets a minimum sinking fund rate linked to construction cost. The optional comparison below shows that figure; it is separate from this estimate.

What is a sinking fund in a housing society?

Money set aside over the years for large future work on the building — major repairs or reconstruction — so members aren't asked for a large one-time amount when the work is due.

What does the Model Bye-law minimum mean?

The Maharashtra Model Bye-laws (2014), bye-law 13(c), set the sinking fund rate as decided by the general body, subject to a minimum of 0.25% a year of each flat's construction cost (excluding land), as certified by the architect. It applies only if your society adopted those bye-laws.

What inflation rate should I use?

Use your engineer's estimate if you have one. Otherwise try two or three rates to see the range — the tool updates instantly.

Is my data stored?

No. The calculation runs in your browser and nothing is saved or sent.

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