Home Affordability Calculator: How Much House Can You Actually Buy?

A couple earning ₹1,00,000 a month combined got pre-approved by their bank for a home loan of ₹75 lakh, and immediately started house-hunting in that budget. What the bank's pre-approval didn't emphasize clearly enough is that a loan of that size, at a realistic 20-year tenure, would consume nearly 60% of their take-home income in EMI alone, leaving them stretched thin on everything else. The bank's maximum sanction and your actual comfortable affordability are two very different numbers.

How banks decide how much to lend #

Banks generally use the FOIR (Fixed Obligation to Income Ratio) method, capping your total EMIs (including the new home loan) at around 40 to 50% of your monthly income, depending on the bank's internal policy and your income level. Some banks go up to 55 to 60% for higher-income borrowers, but a more conservative 40% is a safer benchmark for your own planning, regardless of what the bank is technically willing to sanction.

The affordability formula #

Maximum EMI = Monthly income × Affordability ratio (typically 40%)

Then work backward from the EMI to the loan amount using the standard EMI formula, solved for principal:

Maximum loan = EMI × [(1+r)^n − 1] / [r × (1+r)^n]

Where r is the monthly interest rate and n is the number of monthly instalments.

Worked example: ₹1,00,000 monthly income #

• Monthly income: ₹1,00,000
• Affordability ratio: 40%
• Maximum EMI: ₹1,00,000 × 0.40 = ₹40,000
• Interest rate: 8.5% per annum
• Tenure: 20 years (240 months)

Solving for the loan amount: Maximum loan eligible = ₹46,09,234

Assuming a typical 80% loan-to-value ratio (20% down payment required), the total property value this translates to is:

• Property value = Loan / 0.80 = ₹46,09,234 / 0.80 = ₹57,61,542
• Down payment required: ₹11,52,308

So a ₹1,00,000 monthly income realistically supports a property in the ₹55 to 58 lakh range, once both the EMI affordability and the down payment requirement are accounted for together, not just the loan eligibility banks quote in isolation.

Why the bank's maximum isn't your target #

Banks calculate FOIR based on your gross obligations relative to income, but they don't fully account for your actual lifestyle costs, existing savings goals, or the buffer you'd want for emergencies. Stretching to the bank's maximum sanction often means an EMI that technically fits the bank's formula but leaves little room for anything else in your monthly budget.

How tenure changes what you can afford #

Stretching the loan tenure from 20 to 30 years lowers the monthly EMI for the same loan amount, which in turn raises how much you can technically borrow within the same affordability ratio. But a longer tenure also means paying significantly more total interest over the life of the loan, and it often means still carrying a home loan well into your late 50s or 60s. A shorter tenure with a higher EMI, if it fits comfortably within your affordability ratio, generally results in a lower total cost of the home once all the interest is added up. Affordability calculations should account for this tradeoff explicitly rather than defaulting to the longest tenure a bank offers, simply because it produces the biggest eligible loan amount.

Dual income households and affordability #

For couples applying jointly, banks typically combine both incomes for the FOIR calculation, which increases the loan eligibility substantially compared to a single applicant. This is worth factoring in carefully: if one income is less stable (a commission-based role, a newer business), a more conservative approach is to size affordability primarily around the more stable income, treating the second income as a bonus that accelerates prepayment rather than a permanent fixture of the EMI calculation. This protects the household if the variable income dips in a slow year.

Common mistakes when estimating home affordability #

1. Using the bank's maximum sanction as the target property price. The bank's calculation optimizes for their risk tolerance, not your comfort or other financial goals.
2. Forgetting to include other existing EMIs. If you already have a car loan or personal loan, your FOIR-based home loan eligibility drops significantly, since all EMIs are counted together.
3. Ignoring the down payment requirement. Loan eligibility only tells half the story. You also need to arrange the 20% (or more) down payment plus registration and stamp duty costs separately.
4. Not stress-testing for a rate increase. Since most home loans are floating rate, a 1 to 1.5% rate increase over the loan tenure can meaningfully raise your EMI. Check your affordability at a slightly higher rate than today's, not just the current one.

Tips for a realistic affordability check #

• Use a more conservative ratio (30 to 35%) than the bank's maximum, especially if your income has any variability or you have other financial goals competing for the same money.
• Factor in maintenance, property tax, and society charges, which aren't part of the EMI but are real recurring costs of homeownership.
• Check your affordability at a stress-tested interest rate, a percentage point or two above the current rate, to make sure you're not overextended if rates rise during your loan tenure.
• Don't forget your other goals. Retirement savings, your child's education fund, and an emergency fund shouldn't be permanently paused just to service a large home loan EMI.

Work out your own numbers with the home affordability calculator, and check a real scenario like ₹1 lakh monthly income in Bangalore or ₹2 lakh monthly income in Mumbai to see how affordability shifts by city and income. Once you've settled on a target loan amount, the home loan EMI calculator can help you compare tenure and rate combinations in more detail.

Frequently asked questions #

What percentage of income should go toward a home loan EMI? #

A commonly used conservative benchmark is 40% of monthly income, though banks sometimes sanction loans up to 50 to 60% of income for higher earners. Sticking closer to 30 to 35% leaves more room for other financial goals and unexpected expenses.

Does the bank's loan pre-approval account for my other EMIs? #

Yes, banks factor in all your existing EMIs (car loan, personal loan, education loan) when calculating your FOIR-based eligibility for a new home loan. This is why paying off smaller existing loans before applying can meaningfully increase your home loan eligibility.

How much down payment do I need alongside the loan? #

Typically 20% of the property value, since most banks finance up to 80% for mid-range properties. Budget an additional 5 to 7% for stamp duty and registration charges on top of the down payment itself.

Should I stretch to the bank's maximum sanctioned amount? #

Generally no. The bank's maximum reflects their risk appetite, not your personal comfort level or other financial priorities. A more conservative EMI, one that still leaves room for savings, an emergency fund, and unexpected expenses, is usually the better long-term choice even if it means a smaller or more modest property.

Use the home affordability calculator to find your own realistic range before you start house-hunting, so you're comparing properties you can actually afford comfortably every month, not just ones the bank happens to be willing to finance.