Whether an electric car is cheaper to run than a petrol car, per kilometre, turns on one number that single-tariff comparisons leave out: your blended charging rate. In a flat you may charge on your own meter, at a society point and at public chargers, and each place prices a unit differently. Weight each price by the share of your units drawn there, multiply by the units your car uses per kilometre, and set the result against your petrol cost per kilometre from your own fuel receipts and odometer. A low-mileage driver who pays fixed monthly charging costs, or leans on fast public charging, can find that petrol wins. Nothing here promises a saving.
EV versus petrol in three lines
Fill each line from a document you hold, and the answer follows.
- EV cost per km = your blended rate in rupees per unit × the units your car draws per km.
- Petrol cost per km = rupees on your fuel receipts ÷ kilometres driven on that fuel.
- Monthly difference = (petrol cost per km − EV cost per km) × your monthly kilometres.
One tariff from one bill describes someone who charges in one place; a flat resident needs the first line built from several. The single-tariff method is in our guide to calculating your monthly EV charging cost; this page adds the blend and the petrol side.
For units per km, use your own driving. An owner divides the units on charging receipts by the kilometres driven that month; a buyer resets the trip meter on a long test drive over their own routes, then converts display energy to units at the charger as the monthly-cost guide shows.
Building your blended rate from your own charging mix
Your blended rate is each place's price per unit × the share of your units drawn there, added up. The shares are your own estimate and must total 1. Start from where the car sleeps, whether a society point is open to you, and how many long trips need a fast charger.
| Where you charge | Where your price comes from | What is inside that price | Your share of units | Contribution |
|---|---|---|---|---|
| Own flat meter | Marginal slab rate plus per-unit duty on your bill (reading your bill) | Domestic tariff (cl. 15(4)), or the EV tariff on a separate connection (cl. 15(1)) | a | own rate × a |
| Society or community point | Your society's written rate (how societies bill) | Set by the society "based on" tariff and the service ceiling (cl. 16(7)) | b | society rate × b |
| Public AC point | Displayed rate and your receipt (cl. 10(3); public charging) | Tariff, service charge, land cost, GST as applicable (cl. 8) | c | AC rate × c |
| Public DC fast charger | Displayed rate and your receipt, with any parking or idle fee | Same four; higher service-charge ceiling than AC (cl. 10(1)) | d | DC rate × d |
| Your blended rate | Your own shares | Check: a + b + c + d = 1 | 1 | Sum of the four contributions |
If a public point bills per minute or adds parking, receipt total ÷ units delivered is your real price per unit. If your DISCOM has a time-of-day tariff, your home rate depends on when you plug in; see whether night charging saves money.
What the 2024 guidelines say about each price
The Ministry of Power's Guidelines for Installation and Operation of Electric Vehicle Charging Infrastructure-2024, dated 17 September 2024 (copy on beeindia.gov.in; last verified 15 October 2026), speak to each row.
- Cl. 15(4), own meter: "Domestic electricity rates will apply to charging EVs at home."
- Cl. 4(e) and 16(7), society point: a Community Charging Station is a "semi-public charging station installed at Group Housing Societies", and the Group Housing Society "will determine the charging fees for community charging based on the applicable electricity tariff and service ceiling limits".
- Cl. 8, public points: "The total fee charged by Charge Point Operators from customers shall comprise" the electricity tariff "as pass through", a "Service charge as per Clause 10.0", land cost, and "GST as applicable".
- Cl. 10(1), the ceiling: it caps the service charge alone, "excluding GST & land cost", separately for AC and DC and for solar and non-solar hours, until 31 March 2028, "subject to annual review". It does not cap the displayed total.
- Cl. 10(3), display: stations "will prominently display: a. Charging rates per unit. b. Applicable service charges."
The covering letter is addressed to the Secretaries of Union ministries and the Chief Secretaries of the States/UTs. Clause 2 makes the guidelines "applicable to" owners and operators of charging infrastructure in "Group Housing Societies", but names no penalty for a society, so whether cl. 16(7) binds yours is unsettled: treat it as a yardstick to ask about, not a right to enforce. None of this is legal or tax advice.
The petrol side, from your own fuel log
Skip remembered mileage and today's pump price; use receipts and the odometer over at least three full tanks.
- Fill to full and note the odometer. This fill only sets the start, so leave its receipt out.
- At every later fill, fill to full again, keep the receipt and note the odometer.
- After three or more fills, add the rupees on every receipt except the first.
- Petrol cost per km = those rupees ÷ (last odometer reading − first). Receipts carry the price you actually paid, so no price assumption enters.
Compare like with like: a weekend test drive on open roads is no match for a month of office traffic. If the petrol car would also be new to you, use a test drive and your latest pump receipt, and mark the result provisional.
When the ledger favours petrol
Three conditions push the comparison towards petrol, alone or together.
- A blended rate above your crossover rate. Petrol cost per km ÷ units per km is the highest blended rate at which the EV still matches petrol. A large share at your dearest place, or parking and idle fees on your receipts, push you towards it.
- Fixed monthly costs only the EV brings. A charging-bay fee, the fixed charge on a separate EV connection, or any rise in the fixed charge after a sanctioned-load increase arrive whether you drive or not. Take each from your own bill or the society's written terms.
- Low monthly kilometres. A small mileage turns even a wide per-km gap into a monthly sum that a fixed cost can swallow.
Together these give the running-cost break-even: break-even km per month = EV-only fixed monthly costs ÷ (petrol cost per km − EV cost per km). Drive less than that and petrol is cheaper to run. Any load increase or new wiring must be specified and certified by a licensed electrician (see sanctioned load); the bill-impact guide shows how added units can move your slab.
This page covers running cost only, not purchase price, insurance, battery replacement, resale or subsidy. Add any of those only from your own written quotes; the on-road price gap ÷ the per-km gap then gives the kilometres needed to recover it.
A worked example on stated assumptions
Every figure below is invented for the arithmetic, and none is a going rate anywhere. Substitute your own.
Suppose your petrol log shows ₹5,600 of receipts over 800 km: 5,600 ÷ 800 = ₹7.00 per km. Suppose the EV draws 0.15 units per km at the charger, and the prices you wrote down are ₹8 at the margin on your bill, ₹12 at the society point, ₹16 at public AC and ₹22 at DC.
Reader A has a point in their own bay: 0.8 of units at home, 0.1 at public AC, 0.1 at DC.
- Blended rate = (8 × 0.8) + (16 × 0.1) + (22 × 0.1) = 6.40 + 1.60 + 2.20 = ₹10.20 per unit
- EV cost per km = 10.20 × 0.15 = ₹1.53
- Gap = 7.00 − 1.53 = ₹5.47 per km
- At an assumed 1,000 km a month: 5.47 × 1,000 = ₹5,470 a month in the EV's favour
Reader B rents with no allotted slot: 0.5 at the society point, 0.2 at public AC, 0.3 at DC, plus an assumed ₹500 monthly bay fee.
- Blended rate = (12 × 0.5) + (16 × 0.2) + (22 × 0.3) = 6.00 + 3.20 + 6.60 = ₹15.80 per unit
- EV cost per km = 15.80 × 0.15 = ₹2.37
- Gap = 7.00 − 2.37 = ₹4.63 per km
- Break-even = 500 ÷ 4.63 = 108 km a month, rounded
On these assumptions Reader B's EV is cheaper to run only above about 108 km a month. At 80 km the per-km gap is worth 80 × 4.63 = ₹370, rounded, against the ₹500 fee, leaving petrol ahead by ₹130 a month. Reader B's crossover rate is 7.00 ÷ 0.15 = ₹46.67 a unit, so here the fixed fee, not the unit price, decides the case.
Common questions
At what monthly distance does my EV beat my petrol car on running cost?
Only fixed costs create a break-even distance. With none, the EV wins at any distance whenever its cost per km is lower. With a monthly fixed cost such as a bay fee, break-even km = that cost ÷ (petrol cost per km − EV cost per km). If the EV's cost per km is higher, no distance makes it cheaper to run.
How do I compare my EV's cost per km fairly against my current petrol car?
Measure both over the same period and the same kind of driving, from documents: fuel receipts and the odometer for petrol, charging receipts and sub-meter readings for the EV, counting units at the charger rather than what the battery reports. Leave out costs identical for both cars, such as tolls, and keep in anything only one of them brings.
Do public charger prices include GST?
Clause 8 of the 2024 guidelines lists "GST as applicable" as a component of the fee charge point operators collect, and the clause 10(1) ceiling is stated "excluding GST & land cost". Clause 10(3), the display rule, does not say whether the rate shown includes GST. So read your receipt: total paid ÷ units delivered is your real price per unit. This is not tax advice.
Should I count maintenance in the comparison?
Only with figures you hold: your own service invoices for the petrol car and the dealer's written service-schedule quote for the EV, over the same period. Divide each year's total by your expected kilometres and add it to that car's cost per km. Without those documents, leave maintenance out rather than assume either car is cheaper to keep.
What if I rent, or my society has no allotted slots?
Then your own-meter share may be zero for now, and your blend uses the society and public rows only. Our guides to renting a flat with an EV and charging without an allotted slot cover routes to a point of your own, and making public charging work covers the routine meanwhile.