Fuel Cost Calculator

How to use this calculator

1. Enter the trip distance in miles. For a round‑trip, either enter the total there-and-back distance or run the calculator on a one‑way distance and double the results.
2. Enter your vehicle’s average fuel efficiency in miles per gallon. You can use the EPA rating, your own long‑term average from the trip computer, or a conservative estimate if the route is hilly or stop‑and‑go.
3. Enter the current or expected fuel price per gallon in your area or along your planned route.
4. Review the calculated gallons needed and total fuel cost for the trip.
5. Optionally adjust MPG or fuel price up and down to see best‑case and worst‑case scenarios and build a buffer into your budget.

Inputs explained

Distance

The total route length in miles that you plan to drive. For a there‑and‑back trip, include both directions, or double the one‑way distance. For multi‑stop routes, add up the segments to get a total.

Fuel efficiency (MPG)

Your vehicle’s average miles per gallon. Use a realistic figure based on your driving mix (city vs highway), load, and driving style—your real MPG may be lower than the official rating if you drive fast, haul cargo, or sit in traffic.

Fuel price per gallon

The cost of fuel per gallon in dollars. You can use today’s local price, an average along your route, or a slightly higher number to build in a safety margin for future price increases.

When to use it

• Budgeting a long road trip and estimating how much of your travel budget will go to fuel versus lodging, food, and activities.
• Comparing potential vehicles (for example, a compact car vs an SUV) by seeing how much more fuel the less efficient option will use on the same route.
• Estimating the fuel cost for recurring delivery, rideshare, or service routes so you can price jobs or understand the true cost of driving.
• Helping roommates or carpool groups split fuel costs fairly by turning trip distance into a clear dollar amount before dividing.
• Planning refueling strategy on sparsely served routes by knowing roughly how many gallons you will use between major stops.

Tips & cautions

• Use a conservative (lower) MPG if you expect heavy traffic, lots of stop‑and‑go driving, hills, trailers, or strong headwinds—real‑world conditions often lower efficiency compared with ideal ratings.
• If fuel prices vary along your route, use an average price or run multiple scenarios (for example, lower price near home, higher price in remote areas) to get a range of likely fuel costs.
• For round‑trips with different routes out and back (for example, scenic out, direct return), add up both distances first or run each leg separately and sum the results.
• Remember that even small improvements in driving habits (smoother acceleration, proper tire inflation, moderate speeds) can improve MPG and reduce total fuel spend over many miles.
• If you track your real fuel use over time, plug your actual MPG back into this calculator to improve future estimates for similar routes or driving conditions.
• Assumes fuel efficiency (MPG) and fuel price remain constant over the entire trip; in reality, both can change with speed, terrain, weather, and where you refuel.
• Does not include non‑fuel travel expenses such as tolls, parking, maintenance, depreciation, or insurance—those can be significant on long trips.
• Uses miles and MPG only; metric units like kilometers and liters per 100 km are not directly supported in this version.
• Does not account for factors like elevation changes, cargo weight, or idling time beyond what you approximate in your MPG input.

Worked examples

Deep dive

FAQs

Can I add tolls, lodging, or other trip costs?

This calculator focuses on fuel only. To build a full trip budget, add estimates for tolls, parking, lodging, food, and maintenance on top of the fuel cost shown here.

How should I handle round‑trips or multi‑stop journeys?

Either enter the total miles for all legs as a single distance or run the calculator separately for each leg and add the fuel costs together. For simple out‑and‑back trips, you can usually double the one‑way distance.

What if I use kilometers and liters per 100 km?

This version works in miles and MPG. To approximate metric use, convert kilometers to miles and L/100 km to MPG first, or use a dedicated metric fuel-cost calculator if available.

How accurate will this estimate be in real life?

The accuracy depends on how realistic your MPG and fuel price inputs are. If you base MPG on your own driving history and use current prices, you’ll usually get a solid estimate—but road, weather, and driving style can still move the actual result up or down.

Can I use this for electric vehicles (EVs)?

Not directly. EVs use kWh per mile and electricity prices instead of MPG and gas prices. You can adapt the idea by substituting kWh and cost per kWh in a separate calculator designed for EV energy costs.

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