Free Fuel Consumption Calculator: L/100km & Trip Cost 2026
Calculate your car L/100 km, trip cost and cost per kilometer.
Log kilometers driven and liters refueled to learn your real consumption and what each trip costs you.
By VOV · Last updated: October 21, 2026
How it works
How it works: consumption = liters ÷ kilometers × 100 (L/100 km); efficiency = kilometers ÷ liters (km/L); trip cost = liters × price; cost per km = cost ÷ kilometers. Measure between full refuels for best accuracy.
Use cases
- Calculate how many liters your car uses per 100 km to compare against the spec sheet
- Estimate the total gas cost for your upcoming 800-km road trip before heading out on vacation
- Compare your car's real-world fuel consumption against the manufacturer's claimed figure to spot possible mechanical faults
Frequently asked questions
How do I measure real consumption?
Fill the tank, note the km, drive normally, fill again: divide refueled liters by km and multiply by 100.
Why does it use more in the city?
Starts, traffic lights and idling: urban consumption can be 30-50% higher than steady highway driving.
How do I lower consumption?
Correct tire pressure, steady speed, remove useless trunk weight and avoid jackrabbit starts: you can save 10-15%.
What measurement units can I use in the calculation?
The calculator works with liters per 100 km and kilometers per liter, the most common units in Mexico and Latin America. If your car reads in miles per gallon, convert the figure first to compare correctly.
Does using the air conditioning raise consumption a lot?
Yes, the AC can raise consumption by 5 to 10%, especially in the city with constant stops. On the highway the effect is smaller; at high speed, opening the windows costs almost as much due to drag.