Fuel Cost Calculator
Are you paying too much for your fuel? Does it seem like the price of keeping your tank full is always going up?
Ask any driver - fuel is a massive cost for motorists.
Thankfully, there are ways to save on your fuel bill. Use our calculator to help you save! Choosing the cheapest petrol station, changing your driving style, limiting your mileage, and even changing to a more fuel-efficient car. We've researched how you can save on fuel; this article gives you the answers.
Why should you calculate your fuel cost?
While many of us simply drive, and pay for fuel as and when we need it, calculating your fuel cost can have real benefits. For instance, you might compare the cost of driving to work with the cost of taking public transport, or you might want to split your fuel cost for a car-share.
You might also want to know how much you'll need to spend on a weekend trip or a driving holiday, or to see how much your annual fuel bills would come down if you bought a new more fuel-efficient car.
And if you've decided to try to change your driving habits to achieve more economical use of fuel, a calculator can help you check out whether it's working and how much you've improved your fuel efficiency. Check out our petrol calculator UK (of course it works for diesel too!) to see how you're doing.
You might want to calculate your fuel cost
- for a particular trip,
- for a regular journey, such as your commute, or
- for your annual mileage.
Our fuel calculator lets you calculate petrol cost quickly and easily.
How do you calculate fuel cost?
A fuel cost calculator needs to carry out two calculations.
- First it needs to calculate your fuel consumption for a given mileage or journey. The formula is quite simply the distance times your car's stated fuel efficiency (miles per gallon).
- Then it needs to calculate the fuel cost, that is, the number of litres times the price you pay for the fuel.
That's quite simple… except that fuel efficiency is in miles per gallon, but you'll be buying your fuel in litres. You can simply multiply the mpg by 0.22 to get a figure of miles per litre, but it's so much easier to let the petrol cost calculator do it for you.
11 tips to save fuel and spend less
There are plenty of ways to save fuel. Most of these steps can save you 2-3% of your bill. That might not sound much - but add three or four of them together and you could make a 10% saving. On the average UK mileage of 7,600 miles, a Ford Focus owner could save nearly £60 a year by getting an improvement of 5mpg.
- Don't stomp on the brakes. Drive gently and smoothly. When you accelerate, go up smoothly through the gears without over-revving the engine, and drive in the highest gear appropriate to your speed. This gets the best fuel efficiency out of your engine as you're aiming to always drive it in the RPM sweet spot where it uses least fuel.
- Reduce weight. If you're the kind of person who uses your car as storage space half the time, you could be paying far more than you need for your fuel. The heavier your car, the more fuel it needs to get it going. Keeping your car tidy isn't just cosmetic - it could actually save you money.
- Don't leave your engine idling. When you're stopped by the side of the road, even just for a couple of minutes to nip into the newsagent's or to wait for someone you're picking up, stop your engine. It doesn't need to idle - and it's using fuel (and creating harmful emissions) while it does. Plus, it's probably costing you 60p-£1 for every hour your engine spends idling. (A fuel price calculator won't tell you what you're wasting - but it can be very significant!)
- Check your tyre pressure regularly. Driving with tyres that are not inflated to the correct pressure wastes fuel - a 1% decrease in tyre pressure leads to a 0.3% decline in fuel economy. Since your tyres will lose 1-2 PSI a month, if you don't check them every week or so you'll be wasting a lot of fuel. You could be driving at nearly 10% lower than your car's planned fuel economy.
- Keep your car regularly maintained. Regular servicing and engine checks will keep your car running as efficiently as it's meant to. Changing the air filter regularly is particularly important. If you regularly check your car's fuel efficiency with a petrol price calculator to see if you're getting the right mpg, you may spot a deterioration in your miles per gallon - if so, it's time for a trip to the garage.
- Reduce drag. Spoilers and skirts may look great, but can increase drag and reduce your fuel economy. So can roof racks and top loads - a fully loaded roof rack could add 20% to your fuel costs, as much as 50% if you're carrying two bikes. if you're carrying a load on top of the car, try to place it so that it presents as little area as possible to the front. Rear mounted bike racks have less drag - so do trailers.
- Limit your use of air conditioning. Air con uses an extra 8-10% fuel, so don't use it unless you're really uncomfortable without it. (However, above 55 mph, air con is more efficient than leaving the windows wide open, which creates drag. At lower speeds, just wind down the windows.)
- Use GPS and radio to keep abreast of the traffic news and avoid getting stuck in traffic jams or having to make unexpected detours.
- Plan your journeys efficiently so you don't drive more miles than necessary. Using Google Maps to get directions can be a real time - and fuel - saver. Google Maps also has a distance calculator which can be super helpful in working out your mileage. Use a journey cost calculator before you go, and check your mileage and fuel consumption afterwards to see if you've managed to keep within budget.
- If you have cruise control, use it on trunk roads and motorways. Not only can it save fuel, but it will also stop you accidentally breaking the speed limit.
- Use the right motor oil. This may sound pernickety, but in fact using oil heavier than your manufacturer's recommended grade can reduce your fuel economy by a couple of percent.
And of course, if you find that your car is a gas guzzler whatever you do, there's one last step you can take; buy a more fuel-efficient car. We talk about that in a bit more detail further on.
Track your driving style to see if you're saving fuel
If you adapt your driving style to save fuel - driving more smoothly, using higher gears - or if you work on any of our other tips for fuel saving, you'll want to see how much you've saved.
Some cars now have on-board computers that can do this for you. Otherwise, you'll need to do it yourself using a fuel consumption calculator. Zero the trip counter next time you fill up. The next fill-up after that, note down your mileage, and note how many litres you needed to put in to fill the tank. Then simply put those two numbers into a fuel economy calculator to work out what mpg you're actually getting out of your car.
For best results, you'll want to take a couple of readings before you make any changes, to establish your base point. Then see how much difference the changes make. You should be pleased with the outcome!
Why isn't the fuel price stable?
Fuel prices can yo-yo over time - though somehow it always feels as if they only go up. Although the costs of production might not change very markedly, oil prices change quickly in response to different factors.
These might include:
- political events, such as the tensions between the US and Iran;
- changing government taxes or subsidies;
- the financial markets, which dictate the price of the two big oil indexes, WTI (West Texas Intermediate) and Brent;
- currency movements, particularly the pound against the dollar;
- supply/demand movements, for instance if demand for oil falls.
On top of this, the petrol price you'll pay depends on pricing decisions taken by the retailer. That's why you should use a fuel price checker to make sure you're not paying over the odd for your top-up.
What counts as good fuel consumption?
What counts as good fuel consumption depends on the type of car you're driving - diesel, petrol, or hybrid.
Let's look at the manufacturers' stated mpg figures.
- Diesel cars can get up to 94 mpg. Good consumption starts around 78-80 mpg - if your car's doing less than that, it's not in the top decile.
- Petrol cars are less fuel efficient. The best come in with 70-78 mpg and a lot are clustered around the high 60s.
- Hybrid cars ought to deliver 80-90mpg.
These are manufacturers' stated mpgs which are tested in the laboratory, on a 'rolling road'. On the road, depending on the type of driving (in town, or on the motorway) and the way you drive, you'll probably achieve rather less.
Petrol or diesel: what should I choose to consume less?
Looking simply at fuel consumption, diesel cars win hands down. A good diesel car will get 10 miles more out of the gallon than a good petrol car.
However, if you're looking at cost, diesel cars don't do so well. Diesel costs 3-5% more per litre than petrol, and diesel cars cost more to buy than petrol cars.
Of course, your best bet might be a hybrid car. These are particularly fuel-efficient for short journeys with multiple stops and changes of speed, so they're good for urban drivers. Till now, they've not been so fuel-efficient on the motorway, but new technology is beginning to close the gap there, too.
Which cars have low fuel consumption?
The table below shows cars that are available new in the UK and have low fuel consumption. Older cars generally are less fuel efficient, though it's worth noting that vintage favourite the Citroen 2CV gets 64mpg, according to Low Tech Magazine, even though the base technology dates from the 1940s!
|Peugeot 208 diesel
|Nissan Micra diesel
|Toyota Prius Hybrid
|Toyata Yaris Hybrid
|Vauxhall Astra diesel
|Fiat Tipo diesel
|Ford Focus diesel
|Hyundai Ioniq hybrid
|Citroen C4 diesel
|Suzuki Celerio petrol
|Fiat 500 petrol
|Hyundai i10 Blue Drive petrol
|Renault Clio petrol turbo
Note that these are manufacturers' statistics and your experience on the road is likely to be different - you probably won't manage to achieve the design mpg.
Where can I find the cheapest fuel?
The best way to find the cheapest fuel is to use an online tool to track down the best petrol or diesel prices. Some cars' onboard computers will automatically look for petrol stations with the lowest prices via their online database.
Waze GPS also gives petrol prices, but because it depends on users to input content, it's more reliable in busy urban areas than in remote areas of the country.
You can even finesse things by using a distance calculator for the UK to see if the detour to a cheap fuel station is worth it!
But if you don't have access to those tools when you're out and about, a few rules of thumb could help you find a better deal.
- Most supermarket petrol stations have competitive fuel prices - up to 3p a litre cheaper than the big petrol brands.
- Most motorway service stations charge above average prices.
- Independents vary widely. A local price war could deliver super cheap prices, but usually, they're not the most competitive.
If you're making a trip that includes a large town and a lot of country road driving or motorway driving, fill up at a supermarket in town - it will almost always be cheaper.