Fuel is the visible cost.
It isn’t the whole cost.
Your receipt from the gas station matters. So do the costs that arrive later.
Start with gallons, not a guess.
For a gasoline vehicle, modeled fuel cost is total miles divided by actual miles per gallon, multiplied by the price per gallon. A 26-MPG small-SUV example traveling 36 miles at $4.13/gallon uses about 1.38 gallons, or $5.72 in fuel. This is an estimate; actual delivery driving can differ.
What the founder’s half-tank example tells us.
At about $80 for a refill, using half is about $40. Over eight hours that is $5 per hour for fuel alone. Dividing $40 by $4.13 gives about 9.69 gallons. That does not tell us the exact tank capacity or mileage driven, and it should not be used to infer the founder’s MPG without an odometer reading.
Vehicle size helps choose a starting point, not an answer.
Our selectors use illustrative assumptions: small car 32 MPG, midsize car 28, small SUV 26, midsize SUV 22, large SUV/truck 17 and hybrid 45. These are not measured class averages. Year, engine, route and driving conditions matter; a specific vehicle can differ substantially. Enter your own actual MPG. Electric vehicles require electricity-use inputs and are outside this gasoline model.
Stop-and-go is not a highway road trip.
Delivery can involve frequent stops, time looking for access and idling. The EPA explains that real-world fuel economy varies with conditions and driving behavior. A vehicle’s highway rating may not represent an actual delivery shift. Use measured shift fuel economy where you have it.
Count fuel once. Count wear too.
In separate-cost mode, the calculator subtracts fuel plus your non-fuel cost per mile. In all-in mode, it subtracts your all-in mileage estimate and shows fuel only as a reference. Never add the same fuel expense to both methods. Maintenance, tires, depreciation and allocated fixed vehicle expenses need their own consideration.
Measure a useful MPG.
Record miles driven and fuel added across comparable refills, using a consistent fill level; divide miles by gallons. Several similar shifts are more useful than a single dashboard estimate. Don’t assume every gallon burned in a week belonged to work if the vehicle is also used personally.
Independent educational guidance. Examples are illustrative. Sources and assumptions ↗