Semi truck fill-up cost calculator
Enter your tanks, how much fuel is left and today's diesel price. See the gallons, the cost to fill and your range.
On the tank label or spec sheet.
FILL-UP COST
COST TO FILL
$720
- Gallons to fill
- 180.0 gal
- Total capacity
- 240 gal
- Cost of a full fill from empty
- $960
- Range on full tanks
- 1,560 mi
- Range left right now
- 390 mi
- Fuel cost per mile
- $0.62/mi
Gray is fuel already in the tank; amber is what you are buying. Leave some room at the top: fuel expands as it warms.
Fuel costs you about $0.62 a mile. Every load we book has to clear that and the rest of your costs.
Get loads that cover fuelHow the fill-up cost is calculated
- Total capacity = number of tanks x capacity per tank.
- Fuel in the tanks now = total capacity x the percent left.
- Gallons to fill = total capacity - fuel in the tanks now.
- Cost to fill = gallons to fill x diesel price.
- Range = gallons x your miles per gallon. Fuel cost per mile = diesel price / miles per gallon.
EXAMPLE FILL-UP
Semi truck fuel tanks: what to know
Tank sizes vary from truck to truck, and the number on a brochure may not match what is bolted to yours. Read the label on each tank or the spec sheet, and add every tank. On trucks with a crossover line between the tanks, the levels balance over time; without one, watch each tank separately.
A bigger tank does not make fuel cheaper, but it gives you more choice of where to buy. Fueling where diesel is cheaper, and skipping a stop where it is not, can matter more over a month than any single fill.
From fill-up cost to cost per mile
The number that matters for loads is fuel cost per mile: diesel price divided by your miles per gallon. At $4.00 and 6.5 mpg, fuel costs about 62 cents for every mile, loaded or empty. Plan a whole trip with the trip fuel cost calculator, and see how fuel fits next to your other costs in the profit calculator.
Running a box truck? The same math applies with smaller tanks; see our guides on maintenance costs and start-up costs. Our dispatch fee is a percentage of the loads you haul, and every load is checked against your fuel cost first.
Questions about this calculator
Q-01How much does it cost to fill up a semi truck?
Gallons needed times the diesel price. Gallons needed is your total tank capacity minus what is still in the tanks. Two tanks of 120 gallons at a quarter full need 180 gallons; at $4.00 a gallon that is $720. Enter your own tank sizes and price above for your number.
Q-02What is a semi truck fuel tank capacity?
It depends on the truck and the tanks fitted to it, so check the tank label or the truck's spec sheet rather than a general figure. Add the capacity of every tank. Many tractors have a tank on each side of the frame, sometimes connected by a crossover line.
Q-03Do semi truck fuel tanks fill evenly?
If the tanks are connected by a crossover line, fuel levels even out between them over time. If they are not, fill each tank separately. Either way, the calculator works the same: it adds up the capacity of all tanks and fills from your current level.
Q-04How far can a semi go on a full tank?
Total capacity times your miles per gallon. A truck holding 240 gallons at 6.5 mpg can go about 1,560 miles in theory, but plan fuel stops well before empty, and around price, parking and your hours of service.
Ryan, TruckSwing dispatch desk
UPDATED OCTOBER 2026 · EDITORIAL POLICY
Fuel is a cost. The rate has to cover it.
We check every load against your fuel and running costs before it reaches you. You approve every load.