Your Car Insurance Premium Is Six Numbers Multiplied Together. Here Is What Each One Actually Means.
Car insurance is not one price. It is six separate components stacked together, and only one of them is negotiable.
The formula: Total Premium = [(IDV × OD Rate) - NCB Discount + Add-Ons + TP Premium + CPA] × 1.18
On a new Maruti Swift VXi (₹7.50 lakh, 1,197cc, Delhi RTO), this breaks down to: (₹7,12,500 × 2.8% - ₹0 NCB + ₹0 add-ons + ₹3,416 TP + ₹220 CPA) × 1.18 = ₹27,574 in year one.
By year five, the same car costs ₹9,200-12,000. Not because insurance got cheaper — but because IDV halved and NCB accumulated to 50%.
This page decodes every variable in that formula. No affiliate links. No “get a quote” redirects.
Component 1: IDV — What Your Car Is Worth to the Insurer
IDV (Insured Declared Value) is the maximum the insurer will pay if your car is stolen or totalled. It is not the market resale value. It is the manufacturer’s current selling price of an equivalent new model, minus age-based depreciation.
IRDAI-Mandated Depreciation Schedule
| Vehicle Age | Depreciation | IDV on ₹7.50L Swift |
|---|---|---|
| Under 6 months | 5% | ₹7,12,500 |
| 6 months - 1 year | 15% | ₹6,37,500 |
| 1-2 years | 20% | ₹6,00,000 |
| 2-3 years | 30% | ₹5,25,000 |
| 3-4 years | 40% | ₹4,50,000 |
| 4-5 years | 50% | ₹3,75,000 |
| Over 5 years | Negotiated | ₹1,50,000-2,75,000 |
Critical detail: The “manufacturer’s selling price” means the current model’s ex-showroom price — not what you paid when you bought it. If Maruti increases the Swift price by ₹30,000 next year, your IDV at renewal is calculated on the new price. This works both ways: if a model is discontinued and the replacement is cheaper, your IDV can drop even in year one.
After 5 years: There is no IRDAI formula. The insurer offers an IDV based on its own assessment. A well-maintained 7-year-old Swift selling for ₹3 lakh in the used-car market might get an IDV of ₹1.8-2.2 lakh from the insurer. Always negotiate. Request a higher IDV and cite OLX/Cars24 listings as evidence of market value. Some insurers allow up to 10-15% IDV increase over their initial offer.
Why IDV Matters Beyond Total Loss
IDV directly determines your OD premium. A higher IDV means higher premium — but also higher claim payout. Accepting a lowball IDV saves ₹500-1,000 in premium but costs ₹50,000-1,00,000 if the car is stolen or written off.
Component 2: OD Rate — The Only Truly Variable Number
OD (Own-Damage) rate is the percentage of IDV that determines your OD premium. This is where every insurer is different.
Before 2007: Every Insurer Charged the Same
IRDAI mandated OD rates at 1.5-4% of IDV depending on vehicle age, engine capacity, and zone. Every insurer charged identical premiums. Competition was zero.
After January 2007 (Detariffing): Free-for-All
IRDAI deregulated OD pricing. Each insurer now sets its own rate based on:
- Vehicle model risk profile — claim frequency and severity data for that specific model
- RTO zone — Zone A (metros) vs Zone B (all other cities)
- Fuel type — diesel and CNG vehicles attract slightly higher rates
- Claims history — not just your NCB, but industry-wide loss data for that car model
- Distribution channel — online purchases have lower overhead than agent-sold policies
Typical OD Rate Ranges (2026)
| Vehicle Segment | OD Rate (% of IDV) | Annual OD Premium Range |
|---|---|---|
| Hatchback (800-1,200cc) | 2.0-3.0% | ₹5,000-12,000 |
| Sedan (1,200-1,500cc) | 2.5-3.5% | ₹10,000-18,000 |
| SUV (1,500-2,000cc) | 2.8-4.0% | ₹15,000-28,000 |
| Premium SUV (2,000cc+) | 3.0-4.5% | ₹25,000-50,000 |
| Electric Vehicle | 3.5-5.5% | ₹18,000-40,000 |
How the Same Swift Gets Different Quotes
| Channel | Typical OD Premium | Why |
|---|---|---|
| Online-first insurer (Acko, Digit) | ₹14,000-17,000 | No agent commission, lean operations |
| Private insurer (ICICI Lombard, HDFC Ergo) | ₹16,000-20,000 | Moderate agent commission, granular risk pricing |
| PSU insurer (New India, Oriental) | ₹18,000-23,000 | Higher base rates, wider garage network |
| Aggregator (PolicyBazaar) | ₹15,000-19,000 | Competitive quotes but may push add-on upsells |
The ₹9,000 gap between cheapest and costliest quote on the same car is entirely in OD. TP premium is identical. Add-on pricing varies, but OD is where the real difference lives.
Component 3: NCB Discount — How Claim-Free Driving Pays Back
NCB (No Claim Bonus) applies only to OD premium. TP, add-ons, and CPA are unaffected.
| Consecutive Claim-Free Years | NCB Discount |
|---|---|
| After 1 year | 20% |
| After 2 years | 25% |
| After 3 years | 35% |
| After 4 years | 45% |
| After 5+ years | 50% (maximum) |
Real Impact: Maruti Swift OD Premium Over 5 Years
Assuming ₹19,950 base OD premium in year 1 (2.8% of ₹7,12,500 IDV):
| Year | IDV | Base OD Premium | NCB Discount | Net OD Premium |
|---|---|---|---|---|
| 1 (new) | ₹7,12,500 | ₹19,950 | 0% | ₹19,950 |
| 2 | ₹6,37,500 | ₹17,850 | 20% (₹3,570) | ₹14,280 |
| 3 | ₹5,25,000 | ₹14,700 | 25% (₹3,675) | ₹11,025 |
| 4 | ₹4,50,000 | ₹12,600 | 35% (₹4,410) | ₹8,190 |
| 5 | ₹3,75,000 | ₹10,500 | 45% (₹4,725) | ₹5,775 |
| 6+ | ₹3,75,000 | ₹10,500 | 50% (₹5,250) | ₹5,250 |
Year 1 to year 6: OD premium drops from ₹19,950 to ₹5,250 — a 74% reduction. Two forces compound: falling IDV and rising NCB.
The NCB Trap Nobody Warns About
A ₹6,000 windshield claim in year 4 resets your NCB from 45% to 0%. Next year’s OD premium jumps from ₹5,775 to ₹10,500 — an increase of ₹4,725. The ₹6,000 claim cost you ₹4,725 in lost NCB. Net benefit of filing the claim: ₹1,275.
Rule of thumb: Do not file claims below ₹15,000-20,000 if you have 3+ years of NCB. Pay small repairs out of pocket.
NCB Protection Add-On
Costs 5-10% of OD premium. Allows one claim per year without losing NCB. Worth it when OD premium exceeds ₹12,000 and you have 4+ years NCB accumulated (₹4,500+ at risk per claim).
Component 4: Third-Party Premium — IRDAI-Fixed, Non-Negotiable
TP premium is set by IRDAI. Every insurer charges exactly the same. No discounts, no loading, no variation.
Petrol/Diesel/CNG Private Cars
| Engine Capacity | Annual TP Premium |
|---|---|
| Up to 1,000cc | ₹2,094 |
| 1,001-1,500cc | ₹3,416 |
| Above 1,500cc | ₹7,897 |
Electric Vehicles (15% IRDAI Discount)
| Power Rating | Annual TP Premium |
|---|---|
| Up to 35 kW | ₹1,780 |
| 35-65 kW | ₹2,904 |
| Above 65 kW | ₹6,712 |
CNG/LPG Surcharge
External CNG/LPG kit: ₹60 additional TP premium per year + 4-5% OD loading on the kit value.
Factory-fitted CNG (Maruti S-CNG, Hyundai CNG): only the ₹60 TP surcharge. No OD loading — kit value is already in the ex-showroom price.
CPA (Compulsory Personal Accident)
₹220/year — fixed, mandatory since September 2018. Covers Rs 15 lakh for owner-driver death or permanent total disability. Opt-out only with proof of existing standalone PA cover of ₹15 lakh+.
These TP rates have been unchanged since June 2022. An 18-25% increase is pending MoRTH notification for FY 2025-26.
Component 5: Add-Ons — What Each One Costs and When It Is Worth It
Add-ons are priced individually by each insurer. Here are typical cost ranges for a ₹7.50 lakh hatchback.
| Add-On | Typical Cost | What It Covers | Worth It? |
|---|---|---|---|
| Zero Depreciation | ₹1,200-3,000 (15% of OD) | Eliminates part depreciation deduction on claims | Yes, for cars under 5 years |
| Engine Protect | ₹500-1,200 | Hydrostatic lock damage (flood driving) | Yes, in flood-prone cities |
| Roadside Assistance (RSA) | ₹300-800 | Towing, flat tyre, battery jump, fuel delivery | Optional — check if car brand offers free RSA |
| Consumables Cover | ₹400-1,000 | Nuts, bolts, engine oil, coolant, AC gas during claims | Yes — these add up to ₹3,000-5,000 per claim |
| Return to Invoice | ₹800-2,000 | Pays invoice value (not IDV) on total loss/theft | Yes, for new cars in first 2 years |
| NCB Protection | ₹500-1,500 (5-10% of OD) | 1 claim/year without losing NCB | Yes, if NCB is 35%+ |
| Key Replacement | ₹200-500 | Lost/stolen key replacement | No — key cost is ₹3,000-8,000, easily self-insured |
| Tyre Protect | ₹400-800 | Tyre damage from road hazards | No — tyres are wear items |
| PA for Passengers | ₹100-300 per seat | Accident cover for unnamed passengers | Optional |
The Smart Add-On Stack
For a new car (under 3 years), the three add-ons that pay for themselves:
- Zero Depreciation — eliminates ₹5,000-20,000 out-of-pocket per claim
- Consumables Cover — saves ₹2,000-5,000 per claim on items not covered by default
- Engine Protect — one waterlogging incident costs ₹40,000-2,00,000 without it
Total add-on cost: ₹2,100-5,200/year. One claim recovers the entire investment.
Component 6: GST — 18% on Everything
GST applies at a flat 18% on the entire premium — OD, TP, add-ons, and CPA combined. No exemptions.
Before GST (pre-July 2017), service tax was 15%. GST increased insurance cost by 3 percentage points.
No input tax credit for individuals. Businesses using cars for commercial purposes can claim ITC on the GST component.
The Complete Maruti Swift Premium Breakdown — Year by Year
Model: Maruti Swift VXi Petrol, 1,197cc, Delhi RTO (Zone A), new purchase.
Year 1 (New Car, Zero NCB)
| Component | Calculation | Amount |
|---|---|---|
| Ex-showroom price | ₹7,50,000 | |
| IDV (5% depreciation) | ₹7,50,000 × 95% | ₹7,12,500 |
| OD premium (2.8% of IDV) | ₹7,12,500 × 2.8% | ₹19,950 |
| NCB discount | 0% | ₹0 |
| Net OD | ₹19,950 | |
| TP premium (1,001-1,500cc) | IRDAI-fixed | ₹3,416 |
| CPA cover | IRDAI-fixed | ₹220 |
| Sub-total (pre-GST) | ₹23,586 | |
| GST @ 18% | ₹4,245 | |
| Total year 1 (no add-ons) | ₹27,831 |
With recommended add-ons:
| Add-On | Cost |
|---|---|
| Zero depreciation | ₹2,200 |
| Engine protect | ₹800 |
| Consumables cover | ₹600 |
| Add-on total | ₹3,600 |
| Revised sub-total | ₹27,186 |
| GST @ 18% | ₹4,894 |
| Total year 1 (with add-ons) | ₹32,080 |
Year 3 (25% NCB, IDV at 70%)
| Component | Amount |
|---|---|
| IDV (30% depreciation) | ₹5,25,000 |
| OD premium (2.8% of IDV) | ₹14,700 |
| NCB discount (25%) | -₹3,675 |
| Net OD | ₹11,025 |
| TP premium | ₹3,416 |
| CPA | ₹220 |
| Add-ons (zero dep + consumables) | ₹2,100 |
| Sub-total | ₹16,761 |
| GST @ 18% | ₹3,017 |
| Total year 3 | ₹19,778 |
Year 5 (45% NCB, IDV at 50%)
| Component | Amount |
|---|---|
| IDV (50% depreciation) | ₹3,75,000 |
| OD premium (2.8% of IDV) | ₹10,500 |
| NCB discount (45%) | -₹4,725 |
| Net OD | ₹5,775 |
| TP premium | ₹3,416 |
| CPA | ₹220 |
| Add-ons (none — zero dep not worth it at this IDV) | ₹0 |
| Sub-total | ₹9,411 |
| GST @ 18% | ₹1,694 |
| Total year 5 | ₹11,105 |
Year 8+ (50% NCB, Negotiated IDV)
| Component | Amount |
|---|---|
| IDV (negotiated) | ~₹2,00,000 |
| OD premium (3.0% — rate rises for older cars) | ₹6,000 |
| NCB discount (50%) | -₹3,000 |
| Net OD | ₹3,000 |
| TP premium | ₹3,416 |
| CPA | ₹220 |
| Sub-total | ₹6,636 |
| GST @ 18% | ₹1,194 |
| Total year 8 | ₹7,830 |
At this point, many owners consider dropping OD and going TP-only: ₹3,416 + ₹220 = ₹3,636 + ₹655 GST = ₹4,291/year.
The decision: is ₹3,539 extra per year (for OD cover) worth insuring a car with ₹2 lakh IDV? If you have an emergency fund that can absorb a ₹2 lakh repair, TP-only is rational.
Every Discount That Reduces OD Premium
All discounts apply only to OD. TP is untouchable.
Discount Stacking Example: Maruti Swift, Year 3
| Discount | Mechanism | Saving on ₹14,700 OD |
|---|---|---|
| NCB (25%, 2 claim-free years) | Automatic | -₹3,675 |
| Voluntary deductible (₹2,500) | You choose to bear ₹2,500 per claim | -₹2,940 (20%) |
| Anti-theft device (ARAI-approved) | Steering lock, GPS tracker | -₹368 (2.5%) |
| Online purchase discount | Buy on insurer’s website, no agent | -₹441 (3%) |
| Total discounts | -₹7,424 | |
| Net OD after all discounts | ₹7,276 |
That is a 50.5% reduction from the base OD premium of ₹14,700. Most people only know about NCB. The other three discounts save an additional ₹3,749.
Pay-As-You-Drive (PAYD)
Select insurers (Digit, Acko) offer OD discounts based on annual kilometres driven. Drive under 5,000 km/year and get up to 25% additional OD discount. Verified via telematics (OBD device) or odometer reading at renewal.
Zone A vs Zone B: The Geography Tax
| Zone A (Higher Premium) | Zone B (Lower Premium) |
|---|---|
| Delhi, Mumbai, Chennai, Bengaluru | All other cities and towns |
| Kolkata, Hyderabad, Ahmedabad, Pune |
Premium is based on RTO registration, not where you park or drive. A car registered at Mumbai RTO pays Zone A rates even if the owner moved to Indore three years ago.
The Actual Difference
On a new Maruti Swift:
- Zone A (Delhi RTO): OD premium ~₹19,950 (2.8% rate)
- Zone B (Jaipur RTO): OD premium ~₹16,050 (2.25% rate)
- Annual difference: ~₹3,900
Over 5 years, that is ₹12,000-15,000 extra for a metro registration. Re-registering at a Tier-2 RTO costs ₹5,000-15,000 in transfer fees — it can pay for itself in 2-3 years if you have genuinely relocated.
Electric Vehicle Premium: Why EVs Cost More to Insure
| Factor | Impact on Premium |
|---|---|
| Battery = 40-50% of vehicle cost | Higher IDV, higher OD premium |
| Battery replacement claim: ₹5-7 lakh | Pushes up insurer’s loss ratio for EVs |
| Fewer trained EV mechanics | Longer repair times, higher labour costs |
| TP premium: 15% IRDAI discount | Saves ₹300-1,200/year vs equivalent petrol |
| Net effect | 10-20% higher comprehensive premium vs equivalent ICE |
EV-Specific Add-Ons You Cannot Skip
- Battery Protect Cover (₹1,500-3,000/year) — covers battery malfunction and damage beyond warranty
- Zero Depreciation — without it, 50% deduction on battery replacement means ₹2.5-3.5 lakh from your pocket
- Charger Coverage — home charging unit is not covered under standard policy
Tata Nexon EV vs Nexon Petrol: Premium Comparison
| Component | Nexon EV (₹14.5L) | Nexon Petrol (₹9L) |
|---|---|---|
| IDV (new) | ₹13,77,500 | ₹8,55,000 |
| OD premium (3.5% vs 2.8%) | ₹48,213 | ₹23,940 |
| TP premium | ₹2,904 | ₹3,416 |
| CPA | ₹220 | ₹220 |
| EV add-ons | ₹4,500 | — |
| Sub-total | ₹55,837 | ₹27,576 |
| GST @ 18% | ₹10,051 | ₹4,964 |
| Total | ₹65,888 | ₹32,540 |
The EV costs ₹33,348 more to insure in year one — primarily because of higher IDV and higher OD rate, not TP.
How to Actually Reduce Your Premium: Decision Framework
If your car is under 3 years old
- Buy comprehensive with zero depreciation + consumables + engine protect
- Choose ₹2,500 voluntary deductible (saves ~20% OD with minimal claim-time impact)
- Buy online directly from insurer (skip aggregators if insurer offers same/better price)
- Never file claims under ₹15,000
If your car is 3-5 years old
- Buy comprehensive with consumables cover only (drop zero dep if loading exceeds 20%)
- Increase voluntary deductible to ₹5,000 (saves ~25% OD)
- Maintain NCB rigorously — at this point it is worth 35-45% of OD
- Consider NCB Protection if OD premium exceeds ₹10,000
If your car is 5-8 years old
- Comprehensive with no add-ons
- Maximum voluntary deductible (₹15,000) — saves ~35% OD
- OD premium is already low; focus on maintaining NCB
- Get multiple quotes — OD rate variation is highest for older cars
If your car is 8+ years old
- Run the math: is annual OD premium < 3% of IDV?
- If yes, comprehensive still makes sense
- If OD premium is ₹3,000-5,000 and IDV is under ₹1.5 lakh, switch to TP-only
- TP-only costs ₹3,416-7,897 + ₹220 CPA + 18% GST = ₹4,291-9,578/year
The Numbers That Comparison Sites Do Not Show You
1. OD premium variation across insurers is 40-60%. The same car, same city, same NCB gets wildly different OD quotes. Always get 4-5 quotes.
2. Agent commission is 12-15% of OD premium. This is baked into the price when you buy through an agent. Online purchase saves this — but not all insurers pass the full saving.
3. Your car model has a risk score. Insurers track claim frequency and severity by exact model variant. A Maruti Swift has lower loss ratios than a Hyundai i20 — OD rates reflect this even if both have the same ex-showroom price.
4. Renewal quotes are often higher than new-business quotes. Insurers offer acquisition discounts to attract new customers. At renewal, the “loyalty” price may be 5-10% higher than what a competing insurer offers. Always compare at renewal.
5. IDV negotiation is possible. Insurers present IDV as fixed. It is not — especially for cars over 5 years. Push for a higher IDV if you believe the car’s market value exceeds the insurer’s assessment. The premium increase is marginal (₹500-1,500) but the claim payout difference can be ₹50,000+.
For a breakdown of what happens when you do need to file a claim, see motor insurance claim process — cashless, reimbursement, FIR, surveyor, rejection. To understand which insurer actually pays claims reliably, see every insurer ranked by claim settlement ratio.