Your Car Insurance Premium = OD + TP. Here Is Exactly How Each Part Is Calculated.
Your annual car insurance bill has two parts. One is fixed by the government. The other is set by your insurer using a secret formula. Nobody shows you the math.
Third-Party (TP) premium is identical across every insurer in India. IRDAI fixes it by engine capacity. No discounts, no loading, no negotiation. A 1,200cc Maruti Swift pays ₹3,416. A 2,000cc Toyota Fortuner pays ₹7,897.
Own-Damage (OD) premium is where every insurer charges differently. It starts at roughly 2.5-3.5% of your car’s IDV, then gets adjusted by NCB, zone, deductible, and the insurer’s internal risk model. The same car can be quoted ₹5,000 by one insurer and ₹12,000 by another.
This page gives you the exact formulas, tables, and worked examples so you can verify every line on your policy schedule.
The Complete Premium Formula
Total Premium =
[Base OD Premium]
− [NCB Discount]
− [Voluntary Deductible Discount]
+ [CNG/LPG Kit Premium (if applicable)]
+ [Add-on Covers]
+ [TP Premium (IRDAI fixed)]
+ [PA Owner-Driver Cover ₹750]
+ [18% GST on everything above]Each component is explained below with exact numbers.
Part 1: Third-Party Premium — Fixed by IRDAI
These rates have been unchanged since FY 2023-24. No gazette notification has revised them. A 25% hike is pending MoRTH approval for FY 2026-27.
Private Cars (Petrol/Diesel/CNG)
| Engine Capacity | Annual TP Premium |
|---|---|
| Up to 1,000cc | ₹2,094 |
| 1,001-1,500cc | ₹3,416 |
| Above 1,500cc | ₹7,897 |
Electric Cars (15% IRDAI Discount)
| Motor Power | Annual TP Premium |
|---|---|
| Up to 30 kW | ₹1,780 |
| 30-65 kW | ₹2,904 |
| Above 65 kW | ₹6,712 |
Two-Wheelers
| Engine Capacity | Annual TP Premium |
|---|---|
| Up to 75cc | ₹538 |
| 76-150cc | ₹714 |
| 151-350cc | ₹1,366 |
| Above 350cc | ₹2,804 |
Commercial Vehicles (Goods Carrying)
| Gross Vehicle Weight | Annual TP Premium |
|---|---|
| Up to 7,500 kg | ₹16,049 |
| 7,501-12,000 kg | ₹27,186 |
| 12,001-20,000 kg | ₹35,313 |
| 20,001-40,000 kg | ₹43,950 |
| Above 40,000 kg | ₹44,242 |
TP premium is the same whether you insure with HDFC ERGO or a public sector insurer. No NCB, no zone adjustment, no deductible. It is what it is.
Part 2: Own-Damage Premium — The Variable Part
OD premium depends on five factors. Each is explained with exact numbers.
Factor 1: IDV (Insured Declared Value)
IDV is your car’s depreciated value — the maximum the insurer will pay on total loss or theft. IRDAI mandates depreciation by vehicle age:
| Vehicle Age | Depreciation % | IDV if Ex-Showroom ₹8L | IDV if Ex-Showroom ₹12L | IDV if Ex-Showroom ₹18L |
|---|---|---|---|---|
| Under 6 months | 5% | ₹7,60,000 | ₹11,40,000 | ₹17,10,000 |
| 6-12 months | 15% | ₹6,80,000 | ₹10,20,000 | ₹15,30,000 |
| 1-2 years | 20% | ₹6,40,000 | ₹9,60,000 | ₹14,40,000 |
| 2-3 years | 30% | ₹5,60,000 | ₹8,40,000 | ₹12,60,000 |
| 3-4 years | 40% | ₹4,80,000 | ₹7,20,000 | ₹10,80,000 |
| 4-5 years | 50% | ₹4,00,000 | ₹6,00,000 | ₹9,00,000 |
| Over 5 years | Mutual agreement | ₹2,40,000-₹3,60,000 | ₹3,60,000-₹5,40,000 | ₹5,40,000-₹8,10,000 |
The Year 5 cliff: Depreciation jumps from 40% (Year 4) to 50% (Year 5) — the steepest single-year drop. After 5 years, there is no formula. The insurer proposes an IDV (often 55-70% depreciated), and most owners accept without negotiating.
Base OD premium is approximately 2.5-3.5% of IDV. The old India Motor Tariff 2002 published exact rates:
| Engine Capacity | Zone A (8 Metros) | Zone B (Rest of India) |
|---|---|---|
| Up to 1,000cc | 3.127% of IDV | 3.039% of IDV |
| 1,001-1,500cc | 3.283% of IDV | 3.191% of IDV |
| Above 1,500cc | 3.440% of IDV | 3.343% of IDV |
These were the published tariff rates until OD was detariffed in January 2007. Post-detariffing, each insurer sets its own OD rate. Actual rates in 2026 range from 1.5% to 4.5% of IDV depending on the insurer’s risk model, your car’s make/model claim history, and the city.
No insurer publishes its rate card. The old tariff numbers remain the only public reference point.
Factor 2: Zone (Registration City)
Zone A — Delhi, Mumbai, Chennai, Bengaluru, Kolkata, Hyderabad, Ahmedabad, Pune Zone B — Rest of India
The old tariff difference was marginal — roughly 3% higher in Zone A. But post-detariffing, real-world pricing shows 15-25% higher OD premiums in Zone A due to:
- Higher traffic density and accident frequency
- More expensive authorized service centers
- Greater theft and vandalism risk
- Higher court-awarded claim amounts
Zone is based on RTO registration, not where you drive. A car registered at Mumbai RTO pays Zone A rates even if you relocated to Jaipur. Changing zones requires RTO transfer (₹5,000-15,000 in fees).
TP premium is the same across all zones — zone only affects OD.
Factor 3: No Claim Bonus (NCB)
NCB is a cumulative discount on OD premium for each claim-free year. It does not apply to TP premium, add-ons, or GST.
| Consecutive Claim-Free Years | NCB Discount on OD |
|---|---|
| 1 year | 20% |
| 2 years | 25% |
| 3 years | 35% |
| 4 years | 45% |
| 5 or more years | 50% (maximum) |
The progression is not uniform. Year 2→3 jumps 10 percentage points (25→35%), while Year 1→2 jumps only 5 points (20→25%).
What a Single Claim Actually Costs You in Lost NCB
Filing even one claim resets NCB to zero. Here is the real cost of claiming on a ₹15,000 base OD premium:
| Your NCB Before Claim | Annual OD Saving from NCB | Years to Rebuild to Same NCB | Total NCB Lost Over Rebuild Period |
|---|---|---|---|
| 20% (1 year) | ₹3,000/year | 1 year | ₹3,000 |
| 25% (2 years) | ₹3,750/year | 2 years | ₹6,750 |
| 35% (3 years) | ₹5,250/year | 3 years | ₹12,000 |
| 45% (4 years) | ₹6,750/year | 4 years | ₹19,500 |
| 50% (5 years) | ₹7,500/year | 5 years | ₹26,250 |
A ₹10,000 scratch repair that you claim with 50% NCB costs you ₹26,250+ in lost discounts over the next 5 years. Add the ₹1,000-2,000 compulsory deductible and any voluntary deductible — the total out-of-pocket impact of that claim exceeds ₹28,000.
Rule of thumb: Do not claim if the repair cost is less than your compulsory deductible + voluntary deductible + 3 years of NCB discount.
NCB Protection Add-On
Costs ₹500-800 per year. Allows 1-2 claims per year without losing your NCB.
The math: ₹600 premium protects ₹7,500/year in NCB discount (at 50% NCB on ₹15,000 OD). That is a 12.5x return on the add-on cost. One of the highest-ROI add-ons in motor insurance.
NCB Transfer Rules
- NCB belongs to the person, not the vehicle — it transfers when you switch cars or insurers
- You need an NCB certificate from your old insurer
- Transfer must happen within 90 days of old policy expiry — after that, all accumulated NCB is permanently lost
- Verification between PSU and private insurers sometimes fails — keep your NCB certificate safe
Factor 4: Voluntary Deductible
This is the amount you agree to pay per claim, in addition to the compulsory deductible. Higher deductible = lower OD premium.
Compulsory Deductible (Non-Negotiable)
| Vehicle Type | Compulsory Deductible |
|---|---|
| Car up to 1,500cc | ₹1,000 per claim |
| Car above 1,500cc | ₹2,000 per claim |
| Two-wheeler | ₹100 per claim |
These amounts have not been revised in decades.
Voluntary Deductible Options and the Hidden Cap
Every insurance blog says “save up to 35% with voluntary deductible.” None mention the rupee caps that limit actual savings:
| Voluntary Deductible | OD Premium Discount | Maximum Discount (₹) | Break-Even Claim Size |
|---|---|---|---|
| ₹2,500 | 20% | ₹750 | ₹3,500 |
| ₹5,000 | 25% | ₹1,500 | ₹6,500 |
| ₹7,500 | 30% | ₹2,000 | ₹9,500 |
| ₹15,000 | 35% | ₹2,500 | ₹17,500 |
The cap is the real number, not the percentage. On a ₹10,000 OD premium:
- ₹15,000 voluntary deductible theoretically saves 35% = ₹3,500
- But the cap limits it to ₹2,500
- Meanwhile, every claim costs ₹15,000 + ₹1,000 (compulsory) = ₹16,000 from your pocket
Break-even claim size = Deductible amount + compulsory deductible. If your claim is below this, you are paying more than you receive. If you claim rarely and your OD premium exceeds ₹10,000, the ₹5,000 voluntary deductible offers the best risk-reward ratio — ₹1,500 saved per year against ₹6,000 out-of-pocket risk per claim.
Factor 5: Fuel Type and Kit Add-Ons
Diesel vs Petrol: Diesel variants cost 10-15% more in OD premium due to higher IDV (diesel cars cost more) and higher claim frequency in insurer data.
CNG/LPG Kit: Additional premium = 4% of kit value (OD) + ₹60 flat (TP). A ₹50,000 CNG kit adds approximately ₹2,060/year.
Undeclared kit = claim rejection. If you install CNG/LPG after purchase and do not inform your insurer, any OD claim can be denied on grounds of material non-disclosure — even if the damage has nothing to do with the kit.
Electric vehicles: TP is 15% cheaper (IRDAI mandate). OD is 20-40% more expensive because battery = 40-60% of car value. Net effect: comprehensive EV insurance costs 10-20% more than equivalent ICE cars.
Worked Example: Complete Premium Breakup
Car: 2023 Maruti Swift VXi Petrol (1,197cc), 3 Years Old, Zone A (Mumbai), 35% NCB, ₹5,000 Voluntary Deductible
| Component | Calculation | Amount |
|---|---|---|
| Ex-showroom price | — | ₹6,50,000 |
| IDV (30% depreciation for 2-3 years) | ₹6,50,000 × 0.70 | ₹4,55,000 |
| Base OD premium (~3.2% of IDV) | ₹4,55,000 × 0.032 | ₹14,560 |
| NCB discount (35%, 3 claim-free years) | ₹14,560 × 0.35 | −₹5,096 |
| OD after NCB | ₹14,560 − ₹5,096 | ₹9,464 |
| Voluntary deductible discount (₹5,000) | Cap: ₹1,500 | −₹1,500 |
| Net OD premium | — | ₹7,964 |
| TP premium (1,001-1,500cc) | IRDAI fixed | ₹3,416 |
| PA owner-driver cover | Mandatory | ₹750 |
| Sub-total before GST | — | ₹12,130 |
| GST (18%) | ₹12,130 × 0.18 | ₹2,183 |
| Total premium payable | — | ₹14,313 |
Reality check: Actual insurer quotes for this exact profile range from ₹8,500 to ₹16,000 depending on the insurer. The ₹14,313 above uses the old tariff rate (3.2%). Competitive insurers may offer 2.0-2.5%, while conservative ones may charge 3.5-4.0%.
Same Car, Zone B (Lucknow), Same NCB
| Component | Zone A (Mumbai) | Zone B (Lucknow) | Difference |
|---|---|---|---|
| Base OD rate | ~3.2% of IDV | ~2.7% of IDV | — |
| Base OD premium | ₹14,560 | ₹12,285 | −₹2,275 |
| After NCB + deductible | ₹7,964 | ₹6,485 | −₹1,479 |
| TP (same nationwide) | ₹3,416 | ₹3,416 | ₹0 |
| Total before GST | ₹12,130 | ₹10,651 | −₹1,479 |
| Total with GST | ₹14,313 | ₹12,568 | −₹1,745 |
Zone A costs ₹1,745 more per year for the same car, same coverage, same NCB.
How OD Premium Changes Over Your Car’s Life
Maruti Swift VXi (₹6.5L Ex-Showroom), Zone A, No Claims Ever
| Year | Age | IDV | Base OD | NCB | NCB Discount | Net OD | TP | Total (with GST) |
|---|---|---|---|---|---|---|---|---|
| 1 (new) | 0-6 months | ₹6,17,500 | ₹19,760 | 0% | ₹0 | ₹19,760 | ₹3,416 | ₹28,272 |
| 2 | 1 year | ₹5,20,000 | ₹16,640 | 20% | −₹3,328 | ₹13,312 | ₹3,416 | ₹20,635 |
| 3 | 2 years | ₹4,55,000 | ₹14,560 | 25% | −₹3,640 | ₹10,920 | ₹3,416 | ₹17,716 |
| 4 | 3 years | ₹3,90,000 | ₹12,480 | 35% | −₹4,368 | ₹8,112 | ₹3,416 | ₹14,203 |
| 5 | 4 years | ₹3,25,000 | ₹10,400 | 45% | −₹4,680 | ₹5,720 | ₹3,416 | ₹11,280 |
| 6 | 5 years | ₹3,00,000 | ₹9,600 | 50% | −₹4,800 | ₹4,800 | ₹3,416 | ₹10,095 |
| 7 | 6 years | ₹2,60,000 | ₹8,320 | 50% | −₹4,160 | ₹4,160 | ₹3,416 | ₹9,340 |
| 8 | 7 years | ₹2,20,000 | ₹7,040 | 50% | −₹3,520 | ₹3,520 | ₹3,416 | ₹8,584 |
Year 1 to Year 8: Premium drops from ₹28,272 to ₹8,584 — a 70% reduction. The drop is driven by both declining IDV (lower base OD) and rising NCB (higher discount percentage).
When does TP-only make sense? When OD premium approaches the cost of a minor repair. At Year 8, the OD premium is ₹3,520 — roughly the cost of a bumper respray. At this point, self-insuring own damage (paying repairs yourself) becomes a rational choice if you have an emergency fund.
The Premium Optimization Playbook
Move 1: Set IDV at Midpoint, Not Minimum
Aggregators default IDV to the bottom of the IRDAI range. The midpoint costs ₹800-2,000 more in premium but adds ₹30,000-80,000 to your total-loss/theft payout.
Move 2: Choose ₹5,000 Voluntary Deductible
Best risk-reward ratio. Saves ₹1,500/year (at cap). The ₹7,500 and ₹15,000 options save only ₹500-1,000 more but double or triple your per-claim exposure.
Move 3: Buy NCB Protection
₹500-800/year to protect ₹3,000-7,500/year in NCB discount. The math makes it a no-brainer for anyone with 35%+ NCB.
Move 4: Compare at Identical IDV
When using PolicyBazaar, InsuranceDekho, or direct insurer sites — set IDV to the same number across all quotes before comparing premium. The “cheapest” quote often has the lowest IDV.
Move 5: Do Not Claim Below ₹15,000-25,000
For most car owners with 3+ years of NCB, the break-even threshold for filing a claim is ₹15,000-25,000. Below that, the NCB loss exceeds the claim benefit.
What The Insurer Does Not Tell You
OD rates are secret. Since detariffing in 2007, no insurer publishes its OD rate card. The old India Motor Tariff 2002 rates (3.0-3.4% of IDV) are the only public reference. Actual rates range from 1.5% to 4.5%.
50+ rating variables. Post-detariffing, insurers use proprietary algorithms that factor in make/model claim history, RTO zone, fuel type, driver age, garage network proximity, and in some models, even vehicle color. Two identical cars registered at the same RTO can get different quotes based on the owner’s profile.
TP premium freeze is a ticking bomb. Rates have been frozen at FY 2023-24 levels for three consecutive years while accident frequency and court-awarded compensation amounts have risen 15-20%. When the revision happens (expected FY 2026-27), expect a 25-40% single-year hike.
The constructive total loss threshold. If repair cost exceeds 75% of IDV, the insurer declares your car a CTL (Constructive Total Loss) and pays IDV instead of repair cost. Surveyors sometimes estimate repairs at 74% to avoid paying the full IDV — keeping the car on the insurer’s books at lower cost.
Quick Reference: Every Number You Need
| Parameter | Value |
|---|---|
| TP premium (car ≤1,000cc) | ₹2,094/year |
| TP premium (car 1,001-1,500cc) | ₹3,416/year |
| TP premium (car >1,500cc) | ₹7,897/year |
| EV TP discount | 15% below ICE rates |
| OD rate range (actual, post-detariff) | 1.5-4.5% of IDV |
| OD rate (old tariff reference) | 3.0-3.4% of IDV |
| IDV depreciation: 0-6 months | 5% |
| IDV depreciation: 6-12 months | 15% |
| IDV depreciation: 1-2 years | 20% |
| IDV depreciation: 2-3 years | 30% |
| IDV depreciation: 3-4 years | 40% |
| IDV depreciation: 4-5 years | 50% |
| IDV depreciation: 5+ years | Negotiated (55-70% typical) |
| NCB: 1 year | 20% OD discount |
| NCB: 2 years | 25% OD discount |
| NCB: 3 years | 35% OD discount |
| NCB: 4 years | 45% OD discount |
| NCB: 5+ years | 50% OD discount (max) |
| Voluntary deductible ₹2,500 | 20% discount, max ₹750 |
| Voluntary deductible ₹5,000 | 25% discount, max ₹1,500 |
| Voluntary deductible ₹7,500 | 30% discount, max ₹2,000 |
| Voluntary deductible ₹15,000 | 35% discount, max ₹2,500 |
| Compulsory deductible (car ≤1,500cc) | ₹1,000/claim |
| Compulsory deductible (car >1,500cc) | ₹2,000/claim |
| Compulsory deductible (two-wheeler) | ₹100/claim |
| CNG/LPG kit: OD loading | 4% of kit value |
| CNG/LPG kit: TP loading | ₹60 flat |
| PA owner-driver cover | ₹750/year |
| GST on motor insurance | 18% |
| NCB lapse grace period | 90 days |
| CTL threshold | Repair cost > 75% of IDV |
| Zone A cities | Delhi, Mumbai, Chennai, Bengaluru, Kolkata, Hyderabad, Ahmedabad, Pune |
Data sourced from IRDAI notifications, India Motor Tariff 2002 (last published OD rates), General Insurance Council IDV calculator, and insurer policy schedules. OD premium percentages are indicative — actual rates vary by insurer. TP rates are IRDAI-fixed and identical across all insurers. Verify current rates with your insurer before purchase.