The 20/4/10 Rule for Buying a Car: What Fits Your Salary

Every Diwali the showrooms fill up and the salesman has his line ready: "Sir, EMI is only ₹16,000, you won't even feel it." What he doesn't say is that the EMI runs for seven years, the car loses 15–20% of its value in the first year, and the fuel, insurance and service bills come on top. That is how a lot of salaried families end up with a car that looks great in the parking and quietly eats a quarter of their salary.

The 20/4/10 rule is a simple filter against that. It isn't law and it isn't perfect for India, but it gives you a number to argue with before you sign. Below we run it on ₹50,000, ₹1 lakh and ₹2 lakh monthly salaries, and then see where the rule can bend.

Twenty, four, ten: what each number covers

Three numbers, one for each part of the deal:

• 20: pay at least 20% of the on-road price as down payment, from your own savings.
• 4: take the loan for 4 years at most.
• 10: keep the total monthly cost of the car under 10% of your monthly income. "Total" means EMI plus fuel, insurance, service, parking and tolls, not EMI alone.

The rule comes from American personal finance, where it is applied to gross income. We use in-hand salary here, because that is what actually pays the EMI. In India most people also apply the 10% to the EMI alone and treat running costs as a household expense. We'll show both versions, because the gap between them is big.

One thing before any maths: the rule works on the on-road price, not the ex-showroom number in the ad. Road tax, registration and insurance add a good chunk on top, depending on your state, and the down payment and loan are both sized on that bigger figure.

Why 20%, why 4 years, why 10%

The 20% down payment is mostly about depreciation. Insurers value a car using a fixed schedule: 15% off the showroom price between six months and a year, 20% at one to two years, 30% at two to three, and 50% by the fifth year (ICICI Lombard explains the IDV table here). Borrow 90% of the price, as many lenders allow, and you owe more than the car is worth for the first few years. A 20% cushion keeps you roughly level.

The 4-year cap is about interest and about the car outliving the loan. On an ₹8 lakh loan at 9%, here is what tenure does:

Going from 4 to 7 years cuts the EMI by about ₹7,000 but adds ₹1.26 lakh of interest. And by year six or seven, you are paying full EMI on a car that needs new tyres, a new battery and maybe a clutch. These EMIs, and the ones further down, are from the car loan EMI calculator.

The 10% limit is about everything else. For most families a car is a want, not an investment. Rent or home loan EMI, SIPs, school fees and parents' medical bills should get first claim on the salary.

What running costs really look like

The EMI ends in four years. Fuel, insurance and service don't. Here is a rough monthly picture, assuming 750 km a month and petrol at ₹105 a litre (big-city petrol was roughly ₹102–116 in October 2026). These are our assumptions, not quotes, so put in your own.

So even a fully paid small hatchback costs around ₹7,000 a month to keep on the road. That number changes the whole calculation.

What car fits ₹50,000, ₹1 lakh and ₹2 lakh salary

All loans below are at 9% for 4 years with 20% down. At that rate, every ₹1 lakh borrowed costs ₹2,489 a month.

The strict version: EMI plus running costs under 10%

On the strict rule, someone taking home ₹2 lakh a month should be driving a ₹6.4 lakh hatchback (₹5.14 lakh loan, EMI ₹12,791). Plenty of people at that salary are looking at ₹15–20 lakh SUVs. The rule isn't broken. Cars in India are just expensive compared to salaries, and the strict version says so bluntly.

The common Indian version: EMI alone under 10%

This version is more workable, and it is what we'd use as the outer limit for most families. A rough summary: the car's on-road price should be around five times your monthly in-hand salary, with 20% of it coming from savings.

At ₹50,000 a month, both versions agree: a new car will squeeze you. A good used car bought mostly in cash, or the two-wheeler for a couple more years, is the saner call. At ₹1 lakh, an entry-level small car just about fits. At ₹2 lakh, a ₹10 lakh car is comfortable.

What breaking the rule looks like in rupees

Now the very common case. Take-home is ₹1 lakh, and the family has fallen for a compact SUV at ₹11.5 lakh on-road (say ₹10 lakh ex-showroom). The dealer offers 10% down and 7 years.

Neither column works at ₹1 lakh. The 7-year loan only looks affordable because it spreads the pain: over a quarter of the salary goes to the car for seven years, and interest alone is ₹3.6 lakh. The "correct" 20/4 structure makes the EMI even heavier. That's the rule saying this car is too big for this salary, not that you need a longer loan.

Families often land here one small step at a time. You walk in for the base model and walk out with the top variant because it's "only ₹1,800 more EMI". Over 48 months that's ₹86,400, plus interest.

Then there's being "underwater", owing more than the car is worth. Compare the 7-year loan balance with the insured value (IDV) on the ₹10 lakh ex-showroom price:

If the car is stolen or written off in year two of the 7-year loan, the insurer pays around ₹7 lakh and you still owe the bank about ₹8 lakh. Selling it after a transfer runs into a similar gap.

There's a hidden cost too. Banks count your car EMI when they decide your home loan. On the home loan eligibility calculator, ₹1 lakh income at 8.5% for 20 years (50% of income allowed for EMIs) qualifies for about ₹57.6 lakh. Add that ₹16,652 car EMI and it drops to about ₹38.4 lakh. A car bought this year can shrink the flat you buy in two years.

Where the rule can bend, and where it shouldn't

Real life has fair reasons to stretch the rule:

• A bigger down payment. If you have spare savings that aren't already set aside for something else, putting more down is the cleanest bend. At ₹1 lakh salary with a ₹10,000 EMI cap, ₹4 lakh down plus a ₹4 lakh loan gets you an ₹8 lakh car without touching the EMI limit.
• 5 years instead of 4. The same ₹9,964 EMI over 5 years supports a ₹4.8 lakh loan, so a ₹6 lakh car at ₹1 lakh salary. Fine if you plan to keep the car 8–10 years. Seven years is where we'd draw the line. The 5 vs 7 year car loan comparison goes deeper.
• No rent, no other EMI. Someone living in a paid-off family home, with no home loan, can carry 12–15% on the car without trouble.
• The car replaces real spending. If you already spend ₹6,000 a month on cabs and autos, part of the running cost isn't new money.
• Two steady incomes. Fine to count both, if the EMI can still be paid on one salary for a few months.

And where you shouldn't bend at all: when the down payment would wipe out your savings, when a home loan is planned in the next two or three years, when the job is new or shaky, or when the only way to make the EMI "fit" is a 7-year loan with 10% down. Here the rule is doing its job.

Car loan rates, charges and the fine print

SBI's car loan rates run from 8.40% to 9.35% depending on your credit score and tenure, with loans above 5 years priced slightly higher (SBI's auto loan rate page, updated September 2026). Other big banks advertise starting rates in the 8–9% range, but those go to the best profiles. Dealer and NBFC loans often cost more. We used 9% as a middle number.

A few things to check before signing:

• Your limit is not the bank's limit. SBI's new car loan scheme will finance up to 90% of the on-road price, for up to 7 years, and for salaried borrowers the loan can go up to 48 times net monthly income. The bank's job is to lend. Yours is to stay within the 10%.
• Flat rate quotes. "5% flat" sounds cheap but is close to 9% on a reducing balance. Read flat vs reducing rate before you compare offers.
• Key Facts Statement. Since October 2024, lenders must give a KFS for retail loans, showing the all-in yearly cost (APR) including fees. Charges not in the KFS can't be added later without your consent.
• Prepayment charges. RBI's prepayment directions ban these on floating-rate loans to individuals for non-business use, sanctioned from 1 January 2026. Most car loans are fixed rate, so the lender's own policy applies. It has to be written in the sanction letter and KFS, so read it.
• What's inside the loan amount. Dealers like to roll accessories and an extended warranty into the loan. Then you pay interest on seat covers for four years. Pay for extras separately, or skip them.

No tax break, either. For a salaried person buying a car for personal use, car loan interest gives no tax deduction. The old EV-loan deduction (80EEB) only covered loans sanctioned between April 2019 and March 2023. If you are self-employed and use the car for business, interest and depreciation can be claimed as business expenses, so talk to your CA. GST is already inside the ex-showroom price: 18% on small cars, 40% on bigger cars and SUVs, 5% on EVs since September 2025. On a ₹7 lakh small car, about ₹1.07 lakh is GST, as the GST calculator shows.

Building the 20% down payment

No down payment yet usually means you aren't ready for this car. Put ₹15,000 a month in an RD at 6.5% and you'll have ₹1,86,430 in 12 months, or ₹2,84,250 in 18 months, on the RD calculator. That covers 20% of a ₹9 lakh car in a year, or a ₹14 lakh car in eighteen months. A Diwali bonus can top it up.

It's also a trial run of the EMI. If ₹15,000 a month pinches, you find out before signing.

What not to do: build the down payment by draining the money you keep aside for a job loss or a hospital bill, or take a personal loan for it. A personal loan at 11–14% to fund a car down payment is just a second car loan at a worse rate. Run it on the personal loan EMI calculator and the idea dies. If you're weighing a full cash purchase instead, see car loan vs cash.

A quick checklist before the showroom

1. Is the price I'm working with the on-road price, for the variant I actually planned to buy?
2. Can I pay at least 20% of it from savings, without borrowing any part of the down payment?
3. Is the loan 4 years, or 5 at most?
4. Is the EMI under 10% of in-hand salary, and EMI plus running costs under about 15–17%?
5. Am I planning a home loan soon? If yes, how much will this EMI cut my eligibility?
6. Have I compared my own bank's rate with the dealer's offer, using the KFS and APR?

If most answers are yes, go and enjoy the car. If not, a smaller model or one more year of saving costs you very little.

Written by the Gainly team for general information, not as investment or tax advice. Rates and rules change, so check the latest before you decide; tell us if something here is out of date. Contact