Planning a road trip to Murree, a drive from Karachi to Hyderabad or simply budgeting for your daily commute starts with one question: how much will the petrol cost? With fuel prices changing every couple of weeks, it pays to calculate. This guide shows how to calculate petrol cost step by step, with examples, using our free Petrol Cost Calculator.
The formula
Litres needed = distance (km) ÷ mileage (km per litre)
Cost = litres × price per litre
Example 1: Lahore to Islamabad
- Distance: about 375 km (motorway)
- Car mileage: 14 km/l
- Petrol price: Rs 260 per litre (example)
Litres = 375 ÷ 14 = 26.8 L. Cost = 26.8 × 260 = Rs 6,964 one way, about Rs 13,928 return. Motorway tolls are extra.
Example 2: Daily commute
- 18 km each way, 22 working days a month
- Distance = 18 × 2 × 22 = 792 km
- Mileage 12 km/l → 66 L
- At Rs 260 → Rs 17,160 a month
Sharing the cost
If four friends share the Lahore–Islamabad return trip, each pays about Rs 3,482 for fuel. The calculator has a passengers field for this.
Finding your real mileage
Manufacturer figures are often optimistic. To measure yours:
- Fill the tank completely and reset the trip meter.
- Drive normally.
- Refill completely and note the litres.
- Mileage = km driven ÷ litres added.
What affects mileage
| Factor | Effect |
|---|---|
| AC on | Lower mileage, especially in city traffic |
| City traffic | Lower than motorway driving |
| Tyre pressure low | Lower mileage |
| Smooth driving | Better mileage |
| Heavy load | Lower mileage |
Read fuel-saving driving tips for ways to improve it.
Miles and gallons
If a car manual lists miles per gallon, convert with KM to Miles Converter and Liters to Gallons, or simply measure in km/l yourself.
Budgeting
Add fuel to your monthly budget alongside other bills. Compare with the cost of a bus, ride-hailing or carpooling to see the cheapest option. The Percentage Calculator shows how much a fuel price change affects your monthly cost.
Frequently asked questions
How do I calculate petrol cost for a trip?
Divide distance by mileage to get litres, then multiply by the price per litre.
How do I find my car’s real mileage?
Use the full-tank method: km driven divided by litres refilled.
Does AC affect petrol consumption?
Yes, it lowers mileage, especially in slow traffic.