Diesel Price Build-Up Calculator
See exactly where every rupee of the diesel price goes — base price, excise duty, dealer commission, and state VAT.
Your inputs
State VAT is charged on top of the base price AND the central excise duty AND the dealer commission — not just on the base price. Defaults are representative estimates for September 2026 (central excise duty on diesel was cut to effectively zero in March 2026); enter your own state's current published rates for precision, since these change with government notifications and state budgets.
Estimates only. Figures are indicative and do not constitute financial advice.
About the Diesel Price Build-Up Calculator
"Diesel price calculator," "diesel price breakdown," and "why is diesel taxed less than petrol" are all versions of the same real question: exactly what makes up the price you pay at the pump. The genuinely surprising current answer for diesel specifically — central excise duty on diesel was cut to effectively zero in March 2026, the lowest it's been in years, even as the Indian crude oil basket touched $128.70 a barrel in September 2026, its highest level since April.
The same four components that build up petrol's price apply to diesel: base price (crude oil cost plus refining, freight, and OMC marketing margin), central excise duty, dealer commission, and state VAT. Diesel has historically carried a lower dealer commission and lower state VAT rates than petrol in most states (it's taxed more lightly since it's the fuel of commercial transport, agriculture, and logistics — taxing it heavily has knock-on effects on the price of almost everything else), which is the main reason diesel is consistently cheaper than petrol even when both start from the same crude oil cost. VAT compounds the same way here too — it's charged on the base price plus excise duty plus dealer commission combined, not on the base price alone.
Enter your own base price, excise duty, dealer commission, and state VAT rate (check your state's current published rate for precision) to see the exact price build-up and what percentage of what you pay is actually tax.
How to use this calculator
- Enter the base price (crude, refining, freight, and OMC margin).
- Enter the central excise duty (currently near zero, post the March 2026 cut).
- Enter the dealer commission.
- Enter your state's VAT rate to see the final retail price and total tax share.
Frequently asked questions
›Why is diesel cheaper than petrol?
Diesel typically carries lower central excise duty, lower dealer commission, and lower state VAT rates than petrol in most states — it's taxed more lightly because it's the primary fuel for commercial transport, agriculture, and logistics, and heavily taxing it would push up the price of goods and services broadly.
›Is excise duty on diesel really zero now?
As of the March 2026 cut, central excise duty on diesel was brought down to effectively zero, a multi-year low, as part of the government's effort to ease cost pressure on oil marketing companies — this can change with future budget or policy decisions.
›Is VAT charged only on the base price, or on the tax too?
VAT is charged on the base price plus excise duty plus dealer commission combined — a tax on top of tax — which is why the final retail price is meaningfully higher than the base price alone, even with excise duty near zero.
›Why do diesel prices differ between states?
The base price and central excise duty are the same nationwide, but each state sets its own VAT rate on diesel, and since that VAT applies on top of everything else, even a modest rate difference between neighbouring states shows up clearly at the pump.
›Does a crude oil price spike immediately raise diesel prices in India?
Not necessarily — Indian retail fuel pricing isn't a direct daily pass-through of crude prices; oil marketing companies and government policy (including excise duty adjustments) can cushion or delay the impact of a crude spike reaching the pump.