Free real estate and society calculators
Free calculators for societies, landlords and property teams - late fees, GST on maintenance, rental yield, sinking fund, TDS on rent and more.
Society late fee calculator
Late charge on overdue maintenance, under any of the three common bye-law rules.
Open the calculator →Twelve free calculators for Indian societies, landlords and property teams: late fees and interest on arrears, maintenance per square foot, GST on maintenance, sinking fund, rental yield, TDS on rent, prorated rent, security deposit interest and carpet-to-built-up area. All run in your browser with no sign-up.
Why these exist
Every one of these started as a spreadsheet somebody rebuilt badly. A treasurer working out interest on arrears from the bye-laws at eleven at night, a landlord trying to remember whether TDS on rent applies below fifty thousand a month, a committee arguing about whether maintenance should be per flat or per square foot — the arithmetic is not hard, but it is easy to get wrong and expensive to get wrong repeatedly.
So each tool does one calculation, shows the formula it used, and stops. There is no sign-up, no email gate and no PDF sent in exchange for your details. What you type stays in your browser and is never transmitted to us, which is also why we cannot follow up on it — if you want to talk afterwards, you have to book the call yourself.
The other reason they exist is that they are honest about the limits of a default. Almost every figure in Indian society management is ultimately governed by the society’s registered bye-laws, and a calculator that quietly assumes a standard rate is giving you a number that will not survive contact with your auditor. Where a value depends on your rules, the tool says so instead of guessing.
Society and maintenance tools
These five deal with money owed to the society: what to charge, what to add when it is late, and what the tax treatment is. They are the ones committees and treasurers use most, usually in the week around the billing run.
Late fee calculator
Works out the late charge on overdue maintenance under whichever rule your society has adopted — a flat amount, a percentage of the outstanding bill, or a per-day accrual with or without a cap. The three produce very different numbers on the same arrears, which is why the first question is always which one your bye-laws actually specify.
The important output is not the figure, it is the consistency. A late fee applied to some flats and waived for others stops being a rule and becomes a discretionary act, and discretionary acts get contested successfully.
Interest on maintenance arrears calculator
Separate from the late fee, and often confused with it. Interest accrues on the outstanding principal over time, typically at a rate the bye-laws cap; a late fee is a one-off charge for missing a date. Societies that conflate them either under-recover or charge something they cannot defend.
Model the arrears over the months they were actually outstanding, at your registered rate, and you get the figure that belongs on the recovery notice.
Maintenance per sq ft calculator
Converts a total monthly budget into a per-square-foot rate and shows what each flat size pays under it. This is the calculation behind the most common governance argument in Indian societies: whether a 1,200 sq ft flat should pay twice what a 600 sq ft flat pays, or the same, or something in between.
The tool does not take a side. It shows what each apportionment basis does to each flat, which is what a general body needs in front of it before it votes.
GST on society maintenance calculator
Applies the two thresholds that decide whether GST is charged at all — the per-member monthly contribution limit and the society’s aggregate annual turnover — and shows the effect on the bill when it does apply. Both thresholds have to be considered together; societies frequently check one and conclude they are exempt.
Where a society crosses the line mid-year, the output that matters is the point at which registration became due, not the current month’s figure.
Sinking fund calculator
Sizes the monthly contribution needed to fund known future capital work — lift replacement, external painting, waterproofing, pump overhaul — against the years remaining before it is due. It is the calculation that turns "we should be putting something aside" into a number the general body can approve.
Most societies discover through this that their existing contribution is materially short. That is uncomfortable and better discovered eight years out than in the year the lift fails.
Rental and landlord tools
These six deal with a tenancy rather than a society: what the property yields, what the rent should be after a revision, what has to be deducted, and what a departing tenant is owed.
Rent receipt generator
Produces rent receipts in the format employers and assessing officers expect for HRA claims — landlord name, address, period, amount, and a PAN where the annual rent crosses the threshold that requires one. The threshold is the part people miss, and a claim submitted without it gets queried.
Rental yield calculator
Gross and net yield on a property, with net taking in the costs that actually recur: maintenance, property tax, insurance, expected vacancy and repairs. Gross yield is the number quoted in listings and it consistently overstates what a landlord keeps.
The gap between the two is usually two to three percentage points, which is often the difference between a property that beats a fixed deposit and one that does not.
Rent increase calculator
Applies a percentage or absolute revision and shows the new rent, the annual difference, and the position against the escalation clause in the agreement. Useful before a renewal conversation rather than during it.
Prorated rent calculator
Works out the part-month rent when a tenancy starts or ends mid-cycle, on either the actual days in that month or a flat 30-day convention. The two produce different figures, and the agreement usually specifies which — this is the most common small dispute at move-in and move-out.
Security deposit interest calculator
Where the state or the agreement requires interest on a held deposit, this calculates what is owed over the tenancy. Several states mandate it and many landlords do not realise until it is raised at the end.
TDS on rent calculator
Determines whether tax has to be deducted at source on rent paid, at what rate, and what is left to remit to the landlord. The rules differ for an individual tenant and a business, and the threshold that triggers the obligation catches individual tenants out routinely.
Property tools
One tool, and it settles more arguments than its simplicity suggests.
Carpet area to built-up area converter
Converts between carpet area, built-up area and super built-up area at a stated loading factor, in both square feet and square metres. Since RERA, carpet area is the defined term a buyer is sold on, but maintenance is frequently charged on built-up or super built-up — so a society can be billing on one basis and its members reading another.
Loading factors vary widely between projects, and there is no universal number. The converter asks for yours rather than assuming a market default.
Automate all of this with KeyMatrix
A calculator tells you what a figure should be. It does not raise the bill, apply the charge to the right flats, chase the ones that did not pay, or produce the ledger entry behind it — and that gap is where a treasurer’s month actually goes.
In KeyMatrix these calculations are not a separate step. The apportionment rule is a property of the society, so the per-square-foot figure is applied at billing rather than worked out beforehand. Late fees and interest accrue on the schedule the bye-laws specify, to every overdue flat, without anyone deciding who to charge. GST applies automatically once the thresholds are crossed. The sinking fund contribution is a line on the bill and a fund in the books at the same time.
The tools stay free and stay ungated regardless, because a committee that has done its own arithmetic is a better conversation than one being shown ours.
- Billing that applies the rule. Per-flat, per-sqft or hybrid apportionment as a setting, not a monthly calculation.
- Charges that accrue by themselves. Late fees and interest on the schedule your bye-laws specify, applied uniformly.
- Books that follow the bill. Every charge and receipt posts to a double-entry ledger as it happens.
- Reports the auditor accepts. Statutory registers and audit-ready statements generated from the same records.