Truck Fuel Cost Calculator
Distance, MPG and pump price — get gallons, total fuel cost, and cost per mile for the trip. Add idle hours if you run the bunk overnight.
How this calculator works
Gallons = miles ÷ MPG, plus idle hours × 0.8 gal/hr if you enter them.
Total cost = gallons × price per gallon. Fuel cost per mile = total ÷ trip miles — the number to plug into your cost per mile and load profit math.
Small changes compound fast: at 100,000 miles a year, going from 6.0 to 6.5 MPG at $3.60/gal saves about $4,600 — a set of steer tires and then some.
Frequently asked questions
How do I calculate fuel cost for a trip?
Divide the trip miles by your truck’s MPG to get gallons needed, then multiply by the price per gallon. Example: 600 miles ÷ 6.5 MPG = 92.3 gallons × $3.60 = $332.
What MPG does a semi truck get?
Most loaded Class 8 trucks run 5.5 to 7.5 MPG. Aerodynamics, speed, terrain and load weight move the number: dropping from 70 to 62 mph alone can add close to 1 MPG. Use your real average from your ELD or fuel receipts, not the brochure number.
How much does idling add to fuel cost?
A typical semi burns roughly 0.8 gallons per hour at idle. Ten hours of hotel load overnight is about 8 gallons — nearly $29 at $3.60/gal. The optional idle field adds this to your trip total.
Why is my fuel cost per mile the most important number here?
Fuel is the biggest variable cost in trucking — usually 30–40% of total cost per mile. Knowing your fuel cost per mile lets you quote loads, size fuel surcharges, and spot when a truck problem is quietly burning money.