Society Sinking Fund Calculator

Construction cost per sq ft (₹)

Flat area (sq ft)

Annual rate (% of construction cost)

Years to project (optional)

Annual contribution

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Per month

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Corpus after projection (contributions only)

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Runs entirely in your browser; nothing you type is sent anywhere. Model bye-law figures shown as defaults are examples — your state's model and your registered bye-laws govern.

How the arithmetic works

The model bye-law formula is simple: construction cost of the flat times the annual rate gives the year's contribution, which societies bill monthly alongside maintenance. The corpus projection here is deliberately conservative — it shows contributions only, without interest, so the number you see is a floor. Funds parked in deposits per the bye-laws will grow faster than the projection.

Why societies underfund it

The sinking fund fails quietly: a committee holds rates down, the line gets billed but borrowed against for running costs, and twenty years later a structural repair meets an empty account and a special levy nobody can afford. The protections are procedural — bill at least the prescribed minimum, invest it separately in the society's name, show the balance at every AGM, and let the audit confirm the separation. The calculator's job is the easy part; the discipline is the society's.

Questions societies ask

What rate should we use?

Your registered bye-laws' figure. Maharashtra's model bye-laws prescribe a minimum of 0.25% per annum of the construction cost of each flat — used here as the default example — and the general body may resolve a higher rate. Other states' models differ; the calculator works with whatever your documents say.

Construction cost — as of when?

The convention in the model bye-laws is the construction cost of the flat, commonly taken from the society's records or a certified valuation, not today's market price of the apartment. Land cost is excluded. Many societies adopt a per-square-foot construction figure at a general body meeting and apply it uniformly.

Where should the sinking fund be kept?

Separately — that is the whole point. Model bye-laws direct investment of the fund (fixed deposits with permitted banks are the common practice) rather than leaving it mixed with the operating account, and the audit checks exactly this separation. Interest earned accrues to the fund.

When can the sinking fund be spent?

For the structural purposes it exists for — major repairs, reconstruction — typically with general body approval, and in some states with registrar-side conditions. It is not a rainy-day account for operating shortfalls, and treating it as one is a standard audit qualification.

Is the sinking fund the same as the repair fund?

No. The repair fund handles the recurring cycle — painting, waterproofing, plumbing overhauls — and model bye-laws prescribe its own minimum. The sinking fund is the long-horizon structural corpus. They are billed, parked and reported as separate lines.

How the whole bill fits together is in the maintenance charges guide; the per-flat split lives in the per-sq-ft calculator.

Sinking Fund Calculator for housing societies