Traffic stopped in the city representing engine idling and wasted fuel

Idling Fuel Use: How Much Fuel Can Idling Burn?

February 23, 2026 9 min read

Quick Summary Idling burns fuel while you get zero miles per gallon. DOE’s fuel-economy guidance notes that idling can use roughly one-quarter to one-half gallon of fuel per hour, and it provides a practical rule of thumb about when shutting the engine off can save fuel. If you want to estimate the cost impact for your driving, you can convert idling time into gallons and dollars using your local gas price.

Idling uses fuel and produces 0 MPG (by definition).
DOE provides an approximate gallons-per-hour range for idling.
Short idling time adds up if it happens every day.

What We Know (Sourced)

DOE states that idling uses fuel while going nowhere and provides an approximate range for how much fuel idling can burn per hour. DOE also notes that restarting the engine uses fuel comparable to a short period of idling and offers a practical cutoff for when turning the engine off can save fuel. Source: DOE — Driving More Efficiently.

AFDC’s efficient driving guidance also emphasizes avoiding wasteful fuel use and recommends efficient driving habits. Source: AFDC — Efficient Driving to Conserve Fuel.

How to Estimate the Cost of Idling

To estimate the cost, you need two inputs:

How long you idle (minutes per day or per week)
Your gas price per gallon

Idling Cost ≈ (Idling Hours × Gallons per Hour) × Price per Gallon

Use DOE’s idling fuel-use range to estimate gallons per hour.

Example (illustrative): If you idle 10 minutes per day, that’s about 0.167 hours/day. Over a month, that adds up. Multiply your hours by an estimated gallons-per-hour value and your local price to get a rough cost range.

For trip fuel cost and overall budgeting, our calculators can help:

When to Turn the Engine Off (Rule of Thumb)

One question drivers have is whether restarting “wastes more gas” than idling. DOE addresses this directly: it notes that restarting uses fuel comparable to idling for a short time and recommends turning the engine off if you expect to be stopped longer than that threshold. See DOE’s guidance: Driving More Efficiently.

Safety note: Always prioritize safety and legality. Don’t shut off your vehicle where you need power steering/braking or where stopping rules require the engine to stay on.

What to Do Next

If you want to reduce idle time without changing your commute:

Avoid long warm-ups that aren’t necessary (see our related post: short trips and cold starts).
Combine errands so you don’t add extra cold starts and idle time (see: combine errands to save fuel).
Reduce stop-and-go patterns where possible by choosing smoother routes (see: stop-and-go traffic and MPG).

Why It Matters

Idling is one of the few fuel uses that’s “pure waste” from an MPG perspective: you burn fuel but travel zero miles. Even if the per-hour amount seems small, frequent idling can add up over months. If your goal is to lower your fuel budget, it’s often easier to attack repetitive daily waste than to chase tiny MPG changes on occasional trips.

Estimate Your Monthly Fuel Spending

Use your commute distance, MPG, and gas price to estimate weekly and monthly fuel cost.

Use the Commute Gas Cost Calculator

Frequently Asked Questions

Does idling hurt MPG?

Yes. While idling, you burn fuel but travel zero miles, so your effective MPG during that time is 0.

How much fuel does idling use per hour?

DOE’s guidance notes that idling can use roughly one-quarter to one-half gallon per hour, depending on conditions. See: DOE — Driving More Efficiently.

Is it better to restart the engine or keep idling?

DOE notes that restarting uses fuel comparable to idling for a short period and provides a cutoff for when turning the engine off can save fuel. The best choice depends on safety and how long you’ll be stopped.

What’s the easiest way to see the cost impact?

Estimate your idling hours per month, then multiply by an estimated gallons-per-hour range and your local gas price. For overall fuel budgeting, use our Cost Per Mile Calculator.