calculate

MPG Calculator

Calculate your real miles per gallon from trip miles and fuel used, with L/100km and cost per mile.

Last updated: June 2026 · Free · No sign-up required

Results

Enter values above and click Calculate to see your result instantly.

Quick reference

You drove	Fuel used	MPG
300 miles	15 gal	20.0
350 miles	12.5 gal	28.0
400 miles	11 gal	36.4
450 miles	9 gal	50.0

apps Small jobs, done in one click

Everyday calculators are the workshop drawer of the site — quick utilities for the moments when you need a number now and a phone calculator won't cut it. Age, date difference, GPA, fuel cost, time-to-decimal, password strength — pick a tool and you're one click from your answer.

speed Loads in under a second

Every tool is plain HTML + JavaScript with the calculation logic compiled in. No spinner, no "verifying browser" splash, no five-second wait while ads load. Hit the page, fill the form, get the answer. Slow tools waste your time and ours.

devices Works on every device

Responsive design tested down to a 320px-wide phone screen. The input fields use native number/date keyboards on iOS and Android, the calculate button is thumb-sized, and the result still reads big and bold on the smallest screen. No app to download, ever.

sentiment_satisfied No funny business

No newsletter pop-ups, no "create an account to see the answer", no fake countdown, no fake stock counter, no upsell. Two ad slots per page (clearly labelled as Advertisement) keep the site free — that's the whole business model.

Interpretation guide

MPG (combined)	Meaning
Under 20	Below average — typical for trucks, large SUVs, towing
20–29	Average for most gas cars and crossovers
30–39	Efficient — compact cars, modern sedans
40+	Excellent — hybrids and the most efficient models

Formula & methodology

Formula: MPG = miles driven ÷ gallons of fuel used; L/100km = 235.215 ÷ MPG

Fill your tank completely and reset the trip odometer (or note the mileage).
Drive normally until the next fill-up.
Refill the tank and note the gallons it took and the trip miles.
Divide miles by gallons — that quotient is your real-world MPG.

Worked example: 350 miles on 12.5 gallons → 350 ÷ 12.5 = 28.0 MPG (8.40 L/100km). At $3.50/gal that's $0.125 per mile.

Frequently asked questions

How do I calculate my MPG?

Fill the tank, reset the trip odometer, drive normally, then refill. Divide the trip miles by the gallons it took to refill. Example: 350 miles ÷ 12.5 gallons = 28 MPG.

How do I figure out miles per gallon without a full tank?

You can divide any distance by the fuel burned over it, but the fill-to-fill method is the only accurate one, because the fuel gauge and dash estimate can be off by 5–10%.

What is a good MPG?

For gasoline cars, 30+ MPG combined is efficient and 40+ is excellent (hybrid territory). Trucks and large SUVs typically run 15–22 MPG.

How do I convert MPG to liters per 100 km?

Divide 235.215 by the MPG figure. 28 MPG = 8.40 L/100km. Lower L/100km means better economy, the opposite direction of MPG.

Why is my calculated MPG lower than the window sticker?

EPA ratings come from standardized lab cycles. Real-world driving with cold starts, short trips, air-conditioning, terrain and aggressive acceleration commonly runs 10–20% below the sticker.