MPG Calculator
Calculate the miles per gallon of your vehicle.
The manufacturer-reported MPG (Miles per Gallon) for virtually all modern car models can be found with a quick online search. However, this figure usually represents a specific model’s performance when it is brand new.
If your vehicle is new (or nearly new) and free from any mechanical issues, you can expect your vehicle’s true MPG reading to be close to the manufacturer’s figure. However, many aspects of your vehicle’s performance will naturally deteriorate with continued use – and fuel efficiency is no exception.
For instance, it’s safe to assume that an eight-year-old car’s MPG score will fall somewhat below the figure circulated by the manufacturer. Therefore, if you want to know how fuel-efficient your vehicle really is, you should calculate its real-world MPG rather than going off the manufacturer’s estimate.
Calculate your miles per gallon
Do you want to work out your vehicle’s MPG? Our useful MPG calculator can help!
Simply enter the volume of fuel (in litres) and mileage travelled from your last trip counter reading - and our calculator will estimate your vehicle’s MPG in an instant.
How to calculate your MPG
- Refuel your car to full capacity when the tank is half full.
- Record the volume of fuel added in litres during the fuel stop.
- Reset the trip clock.
- When the tank is half full once again, multiply the new trip mileage by the number of gallons used.
Useful tip: As long as you have recorded the volume of fuel added (in litres) - and the trip mileage between fuel stops, our MPG Calculator can work out an MPG score for your vehicle in an instant!
How do I record number of litres used?
To record the number of litres you’ve used whilst recording your MPG, look at your fuel gauge before filling your tank to capacity. Also take note of the pump reading (in litres) after you’ve added fuel to your car. When the fuel gauge reaches the same position as before your last fuel stop, you’ll have consumed roughly that amount of fuel.
How do I measure how many miles I have driven?
To record the mileage driven between fuel stops, simply set the trip clock to zero when refuelling, then record its reading the next time you stop for fuel.
How do I accurately record my MPG?
You should also carry out your MPG recordings during periods that reflect your usual driving routine. For instance, if you usually drive on motorways and in urban areas, but decide to drive your car to the Scottish Highlands for a week, this would not be the best time to calculate your MPG!
What is a good MPG?
Whilst the benchmark for a good MPG score varies depending on the vehicle type, a score of 50 or more can be considered ‘good’ for any vehicle class. You should expect a hatchback or electric car to provide greater fuel economy than large SUVs, sports or performance cars.
What is a bad MPG?
For most standard cars, an MPG score below 30 does not represent good fuel economy. With that said, a score of around 20 MPG would be more acceptable for a full-size SUV, sports car or pick-up truck.
MPG rating scale
To give you an indication of how your MPG score stacks up against other vehicles on the road, we’ve created a helpful MPG rating scale:
| Miles Per Gallon | Rating |
|---|---|
| 60+ MPG | Excellent |
| 50-59 MPG | Good |
| 40-49 MPG | Average |
| 30-39 MPG | Fair |
| 20-29 MPG | Poor |
| Under 20 MPG | Very Bad |
This scale is most accurate for small and mid-sized cars – and remember, you can be a little more forgiving if your large SUV or performance car scores below average.
Why do I need to know my car’s MPG?
There are several reasons why you may want to work out your vehicle’s individual MPG score:
- MPG is a good indicator of your vehicle’s overall health; if you find that your MPG is significantly below what you expected, this could indicate hidden mechanical faults.
- If you are selling your car privately, disclosing an honest MPG score can help buyers to make an informed decision – especially if fuel economy is a priority for them.
- Finally, if you’re trying to optimise your budget and keep track of your fuel expenditure, it can be helpful to know your vehicle’s MPG.
This can tell you whether your car is economically viable – or whether selling your car and upgrading to a more fuel-efficient model would save you money in the longer term. If you want to know how much your low-MPG car may be worth, you can get a quick estimate with our car valuation tool.