Plan Your Drive
Trip Cost Calculator
Enter distance, MPG, and gas price to see your exact fuel budget — plus cost per mile for smarter route decisions.
The Trip Cost Calculator turns three simple numbers into an instant fuel budget for any drive. Whether you are planning a weekend getaway, a daily commute, or a cross-country road trip, knowing the fuel cost upfront makes budgeting simple. The calculator outputs a cost per mile and cost per 100 miles alongside the total — invaluable when comparing routes or splitting costs with passengers.
How to Use This Calculator
- Enter the total trip distance in miles (one-way or round-trip — your choice).
- Enter your vehicle's MPG. Use highway MPG for freeway-heavy drives, city MPG for urban routes, or combined for mixed driving.
- Enter the current gas price per gallon at your nearest station.
- Click Calculate Trip Cost (or press Enter on any field).
- Review your total fuel cost, gallons needed, cost per mile, and cost per 100 miles.
How the Formula Works
Divide your trip distance by your MPG to find how many gallons you'll burn. Multiply those gallons by the gas price to get the dollar amount.
Example: You're driving 450 miles in a car rated at 32 MPG, and gas costs $3.60 per gallon.
- Gallons needed: 450 ÷ 32 = 14.06 gallons
- Total fuel cost: 14.06 × $3.60 = $50.63
- Cost per mile: $50.63 ÷ 450 = $0.113/mile
- Cost per 100 miles: $11.25
The per-mile figure lets you compare any two vehicles or routes on equal footing regardless of total trip length.
Tips for an Accurate Estimate
- Use real-world MPG, not EPA estimates. Most drivers see 10–15% lower economy in practice. If you've been tracking fill-ups, use that observed average instead of the sticker figure.
- Match MPG to road type. Highway MPG applies to steady 65 mph driving. If your route mixes interstates with city streets, use the combined rating or calculate each leg separately.
- Account for load and terrain. A full car of passengers, a trailer, or mountain passes will reduce effective MPG by 10–20%. Adjust accordingly.
- Check gas prices en route. Prices at highway exits and tourist areas are often 15–25 cents higher. Plan fill-ups at lower-cost stations before entering those zones.
- Include return-trip fuel. If you're calculating one-way cost, double the distance for the round trip unless you know you'll refuel en route.
When to Use a Trip Cost Calculator
- Road trip budgeting. Combine fuel cost with hotels, food, and tolls to know your total travel budget before you leave home.
- Route comparison. A shorter route with more city driving can cost more in fuel than a longer freeway route. Calculate both to find the cheaper option.
- Carpooling splits. The cost-per-mile figure lets you charge passengers a fair share of fuel expenses for any distance.
- Gig economy work. Rideshare and delivery drivers can compare their per-mile fuel cost against platform mileage reimbursement rates to ensure profitability.
- Vehicle purchase decisions. Run the annual trip cost for your current car against a prospective new model to see how long it takes to recover a higher sticker price through fuel savings.
Related tools: MPG Calculator · Fuel Cost Calculator · Fuel Savings Calculator · MPG Comparison Calculator
Related Guides
- What Is MPG and Why Does It Matter? — A simple guide to understanding miles per gallon and fuel efficiency.
Got Questions?
Trip Cost Calculator FAQ
Divide your trip distance by your vehicle's MPG to get gallons needed, then multiply by the gas price. For example, a 300-mile trip in a 30 MPG car at $3.50/gal = (300 ÷ 30) × 3.50 = $35. This calculator does that math instantly.
Use highway MPG for long interstate drives where you maintain steady speeds. For city-heavy routes with traffic lights and stop-and-go, use city MPG or the combined rating. The combined EPA rating is the safest default when you're unsure of the road mix.
No — this calculator estimates fuel cost only. To budget your full trip, add tolls, parking fees, food, and lodging separately.
As accurate as your inputs. Real-world MPG varies by 10–20% from EPA ratings due to speed, terrain, payload, and driving style. For the best estimate, use the MPG you actually observe at the pump rather than the window sticker figure.
Drive at 55–65 mph (every 10 mph over 55 cuts fuel efficiency by 7–14%), keep tires at the correct pressure, remove roof racks when not in use, use cruise control on flat highways, and compare GasBuddy prices along your route before filling up.
Cost per mile is your total fuel spend divided by the miles driven. It's a universal benchmark for comparing two different vehicles or two different routes regardless of total distance.