How much fuel does a car use while idling?

It varies by engine, temperature, accessory load and control strategy. The calculator gives a planning estimate in gallons per hour.

Why use gallons per hour instead of MPG?

When the vehicle is stationary, miles per gallon is not meaningful because no distance is traveled.

Does air conditioning affect idling fuel use?

Yes. Extra electrical and compressor loads can increase fuel use while idling.

Idle Fuel Consumption Calculator

Estimate fuel burned while idling, gallons per hour, idling cost and repeated daily idling cost.

Idle fuel use is estimated in gallons per hour, not miles per gallon, because the vehicle is not moving.

Never idle in an enclosed space such as a garage, carport, or poorly ventilated area.

Engine displacement (liters)

Fuel type

Idle time (minutes)

Fuel price ($/gal)

Air conditioning

Start condition

Estimate fuel burned while idling

Idle fuel searches usually ask for gallons per hour and cost. This calculator estimates fuel burned while parked from engine displacement, fuel type, idle time, fuel price and extra loads such as air conditioning.

F u e l b u r n e d = G a l l o n s p er h o u r \times \frac{I d l e min u t es}{60}

C os t = F u e l b u r n e d \times P r i ce p er g a l l o n

Carbon monoxide safety

Never idle a vehicle in a closed garage or poorly ventilated space. Exhaust can contain carbon monoxide.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

Related Tools

Fuel Cost Calculator

Estimate gas cost for a trip from distance, vehicle MPG and price per gallon, with gallons needed and cost per mile.

Open

Fuel Consumption Calculator

Calculate real gas mileage from odometer readings and gallons added, with MPG, gallons per 100 miles and L/100km.

Open

Car Ownership Cost Calculator

Estimate the total cost of owning a car with fuel, insurance, maintenance, registration fees, finance charges and depreciation.

Open

EV Charging Calculator

Estimate electric vehicle charging time, energy from the outlet, charging cost, added range and cost per 100 miles.

Open