Use this calculator to easily calculate fuel cost and the gallons / liters needed to complete a trip. Calculate gas cost or petrol cost - we support miles and gallons, liters and km, etc.
Fuel Needed & Fuel Cost Calculations
In order to calculate the amount of fuel for a given trip using our fuel cost calculator or otherwise, you need to know the total distance you will be covering and the expected average fuel consumption of your vehicle. It works the same way for cars, trucks, buses, vans, SUVs, and even boats and planes. If you also want to calculate the fuel cost of a trip, then you need to know the price per gallon or price per liter at which you can by.
Our fuel calculator supports entering distances in miles and kilometers. In terms of fuel consumption, it is very versatile as it accepts: miles per gallon, gallons per 100 miles, kilometers per liter and liters per 100 kilometers. In the US, miles per gallon and kilometers per liter would more frequently used, while in most of Europe the preferred metric would be liters to travel 100 km and gallons to cover 100 miles. The result in terms of fuel amount is in gallons or liters, and for fuel cost is in the currency you entered it in (you can simply ignore the currency sign, e.g. $ (USD)).
Variation in fuel consumption
Make sure to account for the variation in fuel consumption when driving within city limits and on highways - usually the consumption is higher in the former case. Always fill your tank with more fuel than you anticipate you would need, especially during winter or when driving through desolate areas or when extreme weather conditions are expected.
Formula for fuel amount
If you are using mpg (miles per gallon), then the formula for calculating the total amount of gas needed is:
Fuel = Distance / Consumptionmpg
For example, if the distance is 500 miles and consumption is 20 miles per gallon, then the fuel you will need for the entire distance is 500 / 20 = 25 gallons.
If you are using gallons per 100 mi to measure consumption, then the formula for calculating the amount of fuel needed is:
Fuel = Distance / 100 x Consumptionper 100 mi
For example, if the distance is 300 miles and the consumption is 5 gallons per 100 miles, you will need 300 / 100 x 5 = 15 gallons of gas.
Both formulas are applicable for metric units - km and liters, just make sure you do not mix metric units.
How to improve fuel economy?
If you wonder how you can improve the fuel efficiency of your vehicle so you can cover more miles (or kilometers) with less fuel, we have some tips that can result in significant savings, especially when applied consistently over time. Here is our list of 10 fuel efficiency tips:
- Drive sensibly - If you drive aggressively - too fast compared to other cars, constantly overtaking other vehicles, and rapid acceleration followed by braking, only to accelerate again wastes a lot of gas. By some estimates, quick starts and hard stops can increase fuel consumption by more than 30%! This is why this is number one in our fuel efficiency list.
- Observe the speed limit - Different vehicles have optimal fuel economy at different velocities, but one way to increase gas mileage is to avoid driving at higher speeds. A small reduction of your speed, say from 70 mph to 60 mph (equivalently: from 115 km/h to 100 km/h) can help you save 10 to 20% due to lower fuel consumption.
- Follow the leader - drive at about the speed of the vehicle in front of you, if they are following the first 2 tips above. This will make sure you need to accelerate and decelerate as little as possible. If possible, overtake drivers who do not follow them, as it will make it very hard for you to do so.
- Check your tires - make sure your tire pressure is at optimal levels as indicated in the owner's manual provided by the auto manufacturer. If the pressure is too low your mileage will decrease significantly, not to mention that the car may become dangerous to drive.
- Smart routing - make sure you take optimal paths to reach your desired destination. Learn the different modes of route selection your GPS employs - the shortest is not always the fastest and idling stuck in traffic will waste fuel. Use services such as Google Maps to check for traffic congestions on the planned route. Using a route you know well can also help improve fuel efficiency, since you will know in advance where it makes sense to increase speed and where it does not, because of a traffic light just ahead.
- Air conditioning - turning it off will most likely improve your fuel efficiency by 10-15%, and will result in you having more power to accelerate quicker when needed. If it is necessary, make sure you do not set it to unreasonably low or high levels. Air temperature in the range between 64°F - 75°F (18°C - 24°C) is comfortable for most people. Due to the law of thermodynamics, each subsequent degree of heating or cooling requires progressively more energy to accomplish and maintain.
- Remove excess weight - make sure you remove any unneeded heavy items you have in your trunk. One of the untold benefits of losing weight is that your car will be a bit more efficient as well.
- Turn cruise control ON - when on a highway, make sure to use your cruise control option. By keeping your speed constant, it will most likely save gas.
- Avoid idling - idling means 0 miles per gallon and the larger the car engine, the more gas is wasted when idling. Avoid excessive idling, when possible, in line with point #5 above.
- Maintain your vehicle - a well-maintained car, truck, van, SUV, etc. will operate at greater efficiency. Exact fuel savings are hard to calculate, as it will depend on the type of maintenance work your vehicle needs.
All the above advice is fine, but what do you do if you have been following the above advice, yet our fuel cost calculator still shows you numbers that are so high you want to cry? Well, it is most likely time for a new car, or it could be just the fuel price fluctuations over which, unfortunately, neither you nor we have much influence, individually. Fuel prices in most places contain license fees and other state or local government taxes, in some places reaching as much as 50% of the final price. Financial market fluctuations, natural disasters or extreme weather, crisis, as well the geographical area you are in and the local fuel suppliers all influence the price of gas. All you can do is try to observe them and predict when you can get a more decent price.
Cite this calculator & page
If you'd like to cite this online calculator resource and information as provided on the page, you can use the following citation:
Georgiev G.Z., "Fuel Cost Calculator", [online] Available at: https://www.gigacalculator.com/calculators/fuel-calculator.php URL [Accessed Date: 20 Oct, 2019].