Is rent really money down the drain?

Interest is the comparable item, not the whole EMI. In the early years of a loan most of the instalment is interest, which is money paid for the use of capital — the same thing rent is. The part that reduces the balance is the part that buys you something.

Why does the answer flip when I change one rate?

Because two assumptions are compounding against each other over decades: what the property does, and what the invested money does. A two-point difference between them dominates everything else on the page.

What if I sell before the horizon?

Set the horizon to how long you will actually stay. Buying trails for the first years because early EMIs are mostly interest, so a shorter stay usually favours renting — and that is before the transaction costs this model leaves out.

Why is the renter investing anything?

Because otherwise the comparison is dishonest. The renter has not spent the down payment and, in most months, pays less than the owner. Ignoring that money would compare a saver with a spender rather than two ways of housing yourself.

Rent vs Buy Calculator

Comparing an EMI against a rent decides nothing: part of an EMI buys an asset, part of it is interest that is gone, and a renter has a down payment they never spent. This runs both paths to the same date and compares what each leaves you worth.

Check the working

A worked example

A fixed case, for reference.

A ₹1 crore property with 20% down and a 20-year loan at 8.5%, against renting the same home for ₹30,000 a month.

Borrowed
$10000000 - 2000000 = 80{,}00{,}000$
Monthly EMI
$\approx 69{,}426$
Ownership costs at 1% a year
$\frac{10000000 \times 1\%}{12} = 8{,}333 \text{ a month}$
The renter invests the down payment and the monthly difference
$2000000 + \max(69420 + 8333 - 30000,\, 0)$

Which path is ahead at twenty years depends entirely on the two rates you assume — property appreciation and the return on invested savings. Change either by two points and the answer can reverse. That sensitivity is the finding, not a defect in the model.

The formula

\text{Buying} = V_0 (1 + a)^{n} - B_n

The property’s value after n years of assumed appreciation, less the loan balance still outstanding.

\text{Renting} = D (1 + i)^{n} + \sum_{m} \max(E + C - R_m,\, 0)(1 + i)^{\frac{n \times 12 - m}{12}}

The down payment invested for the whole period, plus each month’s saving invested from the month it arises.

What each symbol means

V₀: the property price today
a: assumed annual property appreciation
Bₙ: the loan balance outstanding at the horizon
D: the down payment
i: the return assumed on invested money
E: the monthly EMI
C: monthly ownership costs
Rₘ: the rent in month m, rising each year

What this assumes, and where it stops

Assumptions

The loan runs for exactly as long as you stay, and is fully repaid at the horizon.
Property appreciation and the investment return are steady annual rates, which no real market delivers.
The renter genuinely invests the down payment and every month of saving, rather than spending it. In practice this is where the comparison most often breaks down.
Rent rises by the same percentage every year, and the home rented is equivalent to the one bought.
Ownership costs are a flat percentage of the original price each year.

Limitations

Transaction costs are not modelled: stamp duty, registration, brokerage and the cost of selling are all real and all favour renting.
Tax is not modelled, on either side — no deduction on home-loan interest or principal, and no tax on investment gains.
Prepaying the loan, letting part of the property, and moving before the horizon are not modelled.
Security of tenure, the freedom to alter a home you own, and the constraint of being tied to one city are real factors this arithmetic cannot weigh.
This is not a recommendation to rent or to buy. It shows what your own assumptions imply, and small changes to them change the answer.

What this calculator does

Builds the owner’s position: equity in the property, less anything still owed, after appreciation you choose.
Builds the renter’s position: the down payment invested, plus any month where the owner’s outgo exceeded the rent, at a return you choose.
Counts the costs a tenant does not pay — maintenance, property tax and insurance — and a rent that rises every year.
Reports the year buying gets ahead and stays ahead, which is usually the answer people are actually looking for.

Common questions

Different questions about the same money. These use the same conventions, so the numbers are comparable.

EMI Calculator
Calculate the monthly instalment on a loan, with a full amortisation schedule showing how much of each payment is interest.
Inflation Calculator
Find what a sum today is worth in future purchasing power, and what a future target costs in today’s money.
SIP Calculator
Project what a monthly SIP could grow to over time, and see how much of the total is your own contribution versus assumed returns.
Investment Goal Calculator
Start from the amount you want and work backwards to the monthly investment it would take to get there.