Fuel Cost Calculator
Estimate any trip's fuel cost from distance, fuel efficiency and gas price — plus cost per mile and per person.
Calculate
Type a number or a formula — you can use a saved number too.
| Fuel needed | 10 gal (37.9 L) |
| Cost per mile | $0.117 |
| Per person | $35.00 |
| EV comparison | ≈ $12.90 charging |
How to Use the Calculator
Enter your trip distance (one-way — double it for a round trip), your car's fuel efficiency, and the current fuel price. Everything recalculates live: total cost, gallons needed, cost per mile, and each person's share for road trips. Efficiency works in MPG or L/100km, price per gallon or liter — and the custom option lets you type any efficiency, even as a formula or a saved number.
The Fuel Cost Formula
Distance ÷ MPG gives gallons burned; times price gives dollars. With L/100km, convert first: MPG = 235.21 ÷ (L/100km). The calculator handles both, plus km→miles and liter→gallon conversions, so mixed units never trip you up.
Worked Example: 300-Mile Road Trip
300 miles, 30 MPG, $3.50/gallon
Step 1: Gallons needed: 300 ÷ 30 = 10 gallons.
Step 2: Cost: 10 × $3.50 = $35.00.
Step 3: Per mile: $35 ÷ 300 = 11.7¢/mile.
Split 4 ways: $8.75 each.
EV comparison: the same trip on electricity (~4.3¢/mile) would cost about $12.90 in charging.
Tips to Improve MPG
- Ease off the pedal: aggressive acceleration and braking wastes roughly 15% of fuel. Smooth is free.
- Watch your speed: most cars peak in efficiency around 50–60 mph; every 5 mph above 50 costs like an extra $0.20+/gallon.
- Inflate tires: under-inflated tires can cut efficiency 3–5%. Check monthly.
- Drop the weight: 100 extra pounds costs ~1% MPG. Roof boxes are worse — remove them when empty.
- Combine trips: a cold engine is thirsty; one warm multi-stop loop beats five cold starts.
EV Charging Costs: A Quick Note
Electricity math: cost per mile = electricity price ÷ efficiency. At $0.15/kWh and 3.5 miles/kWh, that's 4.3¢/mile — roughly a third of a 30-MPG gas car at $3.50/gal. Home charging is cheapest; fast chargers can cost 3–4× more per kWh, narrowing the gap on road trips. The calculator's EV line uses the home-charging estimate so you can compare apples to apples.
My saved numbers reuse them in any calculator
Save a number once — like your rent or hourly rate — then just type its name instead of the number, in any calculator here. You can also type formulas like 5000 * 1.1 right into any box.
Saved only in this browser — nothing is sent to us.
Frequently Asked Questions
How do you calculate fuel cost for a trip?
Fuel cost = (distance ÷ MPG) × price per gallon. For 300 miles at 30 MPG and $3.50/gal: (300 ÷ 30) × 3.50 = $35.00.
How much gas do I need for 200 miles?
Divide distance by your MPG: 200 ÷ 30 MPG ≈ 6.7 gallons. At $3.50/gallon that is about $23.33.
What is a good MPG?
In the US, 25–30 MPG combined is typical for a sedan, 20–25 for an SUV, and 40+ for a hybrid. Anything above 30 is solid; above 45 is excellent.
Gas vs EV: which costs less per mile?
Usually the EV: at $0.15/kWh and 3.5 mi/kWh, an EV costs ~4.3¢/mile vs ~11.7¢/mile for a 30-MPG car at $3.50/gal. The EV note in the calculator shows your comparison.
How can I save money on fuel?
Drive smoothly (aggressive driving wastes ~15%), keep tires inflated, drop excess weight, use cruise control on highways, and combine errands. The biggest lever is the car itself: 30 vs 20 MPG saves a third of every fill-up.