Idling Fuel calculator

Use this online idling fuel calculator to easily calculate the amount of fuel consumed by your car’s engine while idling. Just fill in the fields below and click the “calculate” button to get your idling fuel cost.

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Idling fuel consumption cost

When a vehicle’s engine is left running when it is not in motion, this is referred to as idling. So in essence, calculating idling fuel consumption is the estimation of fuel consumed by a vehicle when not in use.

Idling isn’t always deliberate: you can idle your vehicle while stuck in traffic or waiting in line at a drive-thru. Truck drivers frequently leave their engines running to generate power to keep cab temperatures stable while they sleep. School buses also idle when waiting for all students to board. Idling, whether purposeful or unintentional, burns the same amount of gasoline and emits the same amount of pollutants.This is why you need the idling fuel calculator to know how much gas you’re losing.

idling fuel calculator

Why you should stop idling your vehicle.

It is bad for the environment

Research has shown that idling increases the amount of toxic fumes in the atmosphere. These emissions contain a variety of toxic chemicals, including carbon monoxide, which is terrible for the environment and contributes to climate change.

It is bad for your Vehicle

Idling your vehicle for a long period of time can have harmful effects on your engine’s life. This is because your engine isn’t operating at its peak temperature when you idle, the fuel doesn’t completely combust, leaving residue behind that can eventually damage your exhaust system.

 It is prohibited

In New York City, vehicle idling is illegal if it lasts more than 3 minutes or more than 1 minute when adjacent to a school. This includes buses and delivery trucks. Same rule applies in New Jersey. In Colorado and California, idling for more than 5 minutes is prohibited. The same rules also apply in Massachusetts except the vehicle is being serviced or used to deliver or accept goods where engine assisted power is necessary. Offenders can pay up to $500 fine

It is therefore advisable to always turn off your car engine when stopped for more than 30 seconds.

The Factors That Affect Idling Fuel Consumption?

There are a number of factors that affect fuel consumption at idle. The idle calculator above gives you some insights and you can adjust all the input variables to see their effect. Here are some of the factors that affect idling fuel consumption :

Engine Size (larger engines consume more gasoline)

Fuel type (petrol often requires more fuel to idle)

Idle speed (higher engine speed consumes more fuel)

Engine temperature (a cold engine uses more fuel)

 Temperature of intake air (warmer air often consumes less gasoline since it is less dense)

How Much Fuel Fuel is My Vehicle consuming while Idling?

According to SCDHEC, most vehicles will use less than 1 litre per hour to idle, depending on the type and size of engine. So in theory you could leave your vehicle idling for well over 2 days, assuming that the air condition and all other auxiliary loads are switched off before it runs out of fuel. Someone might also ask “How much gas does a 4 cylinder car use idling?”  or  “how much fuel does my 2 Liter engine burn while idling? “ See the answers below

Calculating Idling fuel consumption

According to, Ecomobile, The estimated fuel consumption of an idling engine is 0.6 litres / hr per litre.

Using the chart below, you can determine how much fuel your car burns while idling

Vehicle typeFuel TypeEngine size [L]Idle Fuel [L/hr)
Compact SedanGas20.6
Compact SedanDiesel20.6
Large SedanGas4.61.5
Medium heavy truckGas5 – 73.2
Delivery TruckDiesel 3.2
Medium Heavy TruckDiesel6-101.7
Idling fuel cost table


In order to calculate the amount of idling fuel for a vehicle or equipment First, you need to know the idling time. You can do this by manually recording the time or using the onboard telematics system that tracks engine activity.  Second, determine the idle fuel consumption rate (use the chart above). Then multiply the idling time by the consumption rate.

For example, let’s say you have a car with an engine size of 2 liters (your idle fuel consumption rate is 0.6L/hr) and you leave your car Idle for 2 hours. Your total idle fuel = 0.6 * 2 = 1.2 . This means, when you idle your car for 2 hours , you burn 1.2 liter of fuel. Or better, just use the idling fuel calculator and save yourself the stress.

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