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Loan · FINANCIAL TOOLS

Home Loan Affordability Calculator

Work backwards from your income to the loan and property budget an instalment would support.

Understand the calculation

Calculation logic, formula, example and guardrails behind the estimate.

How it works

The calculation runs in four steps, and the table above shows each of them. Your income is multiplied by the share you are prepared to commit to instalments. Existing commitments come off that. What remains is the instalment available for a new loan. That instalment is then discounted back into a principal.

That last step is the EMI formula run backwards. The EMI calculator takes a principal and produces an instalment; this one takes an instalment and produces a principal. Both use the same engine, so a figure from here fed into the EMI calculator returns the instalment you started with.

More detail

Adding your down payment to the borrowable amount gives a property budget. That is the number worth carrying into a property search, since it is what you could actually put on the table.

The share of income is an input rather than a fixed rule because it is a decision, not a fact. Committing half your income to an instalment is arithmetically possible and may be a poor idea; committing a quarter is more comfortable and buys less. The calculator will compute either.

Once you have a loan amount in mind, the home loan EMI calculator.

To see what paying extra later would save, use the prepayment calculator.

Formula

P = E × (1 − (1 + r)⁻ⁿ) ÷ r, where E = (I × s) − Eₓ

The standard reducing-balance annuity solved for principal instead of payment. r is the annual rate divided by twelve; n is the tenure in months.

P
Loan the instalment would service.
E
Instalment available for the new loan.
I
Monthly take-home income.
s
Share of income committed to all instalments — your assumption, not a lender's rule.
Eₓ
Instalments already being paid each month.
r
Monthly interest rate.
n
Tenure in months.
Worked example

A ₹1,50,000 monthly income with ₹10,000 of existing instalments, committing 40% of income, at an assumed 8.5% over 20 years, with ₹15,00,000 as a down payment.

  1. 01Instalment budget40% × ₹1,50,000 = ₹60,000
  2. 02Less existing instalments₹60,000 − ₹10,000 = ₹50,000
  3. 03Monthly rate8.5% ÷ 12 = 0.7083%
  4. 04Loan that ₹50,000 services over 240 monthsAbout ₹57,60,000
  5. 05Plus down payment+ ₹15,00,000
  6. 06Property budgetAbout ₹72,60,000

Feeding that loan figure into the EMI calculator returns ₹50,000 a month, which confirms the two calculators agree. Raising the tenure or lowering the rate would raise the loan; committing a smaller share of income would lower it.

Frequently asked questions

Common questions about the home loan affordability calculator and the assumptions behind it.

Disclaimer

This calculator is provided for general information and planning only. It is not investment, tax or legal advice, and it does not take your personal circumstances into account. Outputs are estimates based on the assumptions stated on this page, exclude taxes and charges unless said otherwise, and market-linked returns are not guaranteed — the value of investments can fall as well as rise. Lending terms, rates and eligibility are decided by the lender. For advice on your own situation, speak to a qualified professional, several of whom you can consult on Finvestalk.