How Is Car Insurance Premium Calculated in India?

Most people open the renewal notice, look at the total, wince a little and pay it. I did the same for years. What nobody tells you is that the number on that notice is not a bill. It is an offer. Part of it is fixed by the government and will be the same at every company. The rest is the insurer's own price, and that part moves a lot depending on whom you ask and what you accept.

If you remember only one thing from this page, remember that. You can't negotiate the third-party part, but you can question almost everything else.

So before I show you the maths, open your current policy schedule (the PDF your insurer emailed you) and keep it next to you. Everything below will make more sense when you can see your own numbers.

Which part of my premium is fixed, and which part can I change?

Your comprehensive premium is three separate charges added together, and then 18% GST is put on top of the total.

The third-party part for a petrol or diesel car is ₹2,094 up to 1,000 cc, ₹3,416 for 1,001 to 1,500 cc, and ₹7,897 above 1,500 cc, before GST. Electric cars have their own lower slabs based on motor power. These rates have been in force since 1 June 2022. There has been talk of a hike, but nothing new had been notified when we last checked.

Everything else on your notice is the insurer's call.

How is the own-damage premium worked out?

It starts with your car's IDV, the value the insurer agrees your car is worth this year. IDV is the current ex-showroom price of your model, less a fixed depreciation for its age (5% at under six months, going up to 50% at five years). You can check your figure in our IDV calculator.

A rate is then applied to the IDV. Insurers still use the old India Motor Tariff rates as a reference point. For a car under five years old, they look like this:

Zone A is Ahmedabad, Bengaluru, Chennai, Hyderabad, Kolkata, Mumbai, New Delhi and Pune. The rate goes up a little for cars aged 5 to 10 years and again after 10.

Then the discounts come off, in this order:

1. Voluntary deductible discount, if you agree to pay part of each claim yourself.
2. Anti-theft discount for an ARAI-approved device (2.5%, capped at ₹500).
3. The insurer's own discount. This is the big one, often 40% to 70% of the reference figure.
4. Your No Claim Bonus, from 20% to 50%.

That fourth step is why two people with the same car can pay very different amounts.

Why did my premium go up when I made no claim?

This is the question I hear most often, and there are usually four reasons:

• The ex-showroom price of your model went up. IDV is calculated from the current price, not what you paid. If the manufacturer raised prices, your IDV can stay flat or even rise even though your car is a year older.
• Your NCB wasn't applied, or was applied at the old slab. If you had 25% last year and made no claim, you should be on 35% now. Check the schedule line by line.
• Add-ons were added by default. Renewal notices often include roadside assistance, engine protection or key replacement you never asked for.
• The insurer simply priced you higher. Your loyalty doesn't earn you a better rate. Insurers often price new customers more sharply than renewals.

If none of these explain it, ask the insurer in writing for a breakdown. You are entitled to know what you are paying for.

Why do two insurers quote such different amounts for the same car?

Because only the third-party part is regulated. On own damage, each insurer applies its own discount, sets the IDV slightly higher or lower, and prices add-ons in its own way. A 15% to 25% gap between two quotes for the same car is normal.

The trap is comparing totals. A quote can be cheaper only because it has a lower IDV or drops an add-on you had last year. Compare quotes at the same IDV with the same add-ons, otherwise you are comparing different products.

Is the cheapest quote the best one?

Not always, and here is what I'd check before choosing it:

• IDV. Is it close to the calculated value, or quietly cut?
• Add-ons. Does it have the same zero depreciation, engine protection and so on?
• Garages. Is there a cashless network garage near your home or office? A cheap policy with no nearby cashless garage means paying up front and waiting for reimbursement.
• Claim limits on add-ons. Some zero-dep covers allow two claims a year, some only one.

If two quotes are equal on all four, take the cheaper one without guilt.

How can I reduce my premium without reducing my cover?

These are the moves that actually work:

1. Protect your NCB. At 50% NCB, half of your own-damage premium disappears. Paying small repairs yourself is often cheaper than losing that. See our claim or pay yourself calculator.
2. Compare at least three quotes at the same IDV. Switching insurers is allowed, and your NCB moves with you.
3. Drop add-ons you don't use. If your car maker gives free roadside assistance, you don't need to buy it again.
4. Skip the owner-driver PA cover only if you already have a personal accident policy of at least ₹15 lakh. Otherwise it is compulsory.
5. Consider a voluntary deductible only if you rarely claim. The deductible calculator shows whether the saving is worth it.

Should I lower the IDV to save money?

No, and I feel strongly about this one. Lowering IDV saves a few hundred rupees on the premium. If the car is stolen or written off, you lose the full gap between that low IDV and what the car was worth, which can be lakhs. Some insurers also question claims where the IDV was set far below the normal range. The saving is tiny and the risk is huge.

Does my city change my premium?

Yes, a little. The eight Zone A metros carry a slightly higher own-damage rate because accidents and thefts are more common there. For a 1,197 cc car it is roughly a 3% difference in the own-damage part. Where the car is registered matters more than where you live, so keep your registration address updated.

Does fuel type matter?

Petrol and diesel are rated the same way, by engine size. A CNG or LPG kit fitted after purchase adds 4% of the kit's value to the own-damage premium and ₹60 to the third-party premium, and it must be declared on the policy. Electric cars have lower third-party rates based on kW. Their own-damage pricing varies a lot by insurer, so check real quotes.

A real example you can check yourself

Take a 1,197 cc petrol car registered in Indore (Zone B), renewed exactly two years after registration. Ex-showroom price ₹7,00,000, NCB 25%, no add-ons.

That is the reference price with no insurer discount. A real quote for this car might show own damage of ₹6,000 to ₹9,000. The third-party line will be ₹3,416 everywhere.

How do I use this on my own quote?

Put your car's details in the car insurance premium calculator. Then raise the "insurer discount" until our own-damage figure matches the quote in front of you. That number is the real discount that insurer is giving you. Do it for each quote at the same IDV, and you'll see in a minute which one is genuinely better value.