Fuel is one of the most visible costs inside a mileage reimbursement rate, but it is not the only cost employers should consider. A reimbursement rate may also need to account for maintenance, tires, insurance, depreciation, registration, taxes, repairs, parking, and tolls.
Employers can estimate the fuel portion of a reimbursement rate by using a simple formula: divide the local fuel price per gallon by the vehicle’s miles per gallon. The challenge is that fuel prices, MPG, traffic, terrain, weather, and employee mileage can vary across a workforce.
Quick Answer: How Do You Calculate Fuel Cost per Mile for Reimbursement?
To calculate fuel cost per mile, divide the fuel price per gallon by the vehicle’s miles per gallon.
Fuel price per gallon ÷ MPG = fuel cost per mile
For example, if gas costs $5.50 per gallon and the vehicle gets 22.5 miles per gallon, the fuel cost is about $0.2444 per mile.
This only estimates the fuel portion of reimbursement. Employers should also review other business vehicle costs, including maintenance, tires, insurance, depreciation, registration, taxes, and repairs.
Many employers use a mileage reimbursement rate or car allowance to support employees who use personal vehicles for work. But fuel is only one part of the total cost of business driving.
The IRS standard mileage rate is often used as a benchmark. For 2026, the IRS business mileage rate is 72.5 cents per mile for January 1 through June 30 and 76 cents per mile for July 1 through December 31. The IRS also explains that when the standard mileage rate is used, employees cannot separately deduct actual car expenses such as gasoline, oil, insurance, maintenance, repairs, depreciation, or registration fees for that same year.
For employers, the key point is that fuel should not be reviewed in isolation. A fuel card or separate gas reimbursement may help with gas costs, but it may not address the full cost of business vehicle use.
A single fuel reimbursement rate may be easy to administer, but it can miss the mark when employees drive different vehicles, work in different regions, or face different driving conditions.
Fuel cost per mile depends on:
For example, an employee driving a fuel-efficient vehicle may have a much lower fuel cost per mile than an employee driving a larger vehicle. Employees in high-traffic or mountainous areas may also experience different MPG than employees driving mostly on flat roads or highways.
That is why employers should be careful about using one fuel assumption for every employee.
The basic formula is:
Fuel price per gallon ÷ miles per gallon = fuel cost per mile
For example:
This calculation can help estimate the fuel portion of a reimbursement rate. However, it does not include other vehicle costs such as maintenance, tires, insurance, depreciation, registration, taxes, oil, repairs, parking, or tolls.
Employers that want a more consistent methodology may use a company-selected standard vehicle instead of each employee’s personal vehicle. A standard vehicle can help create a more consistent reimbursement assumption, especially when employees drive different vehicles with different MPG.
Fair fuel reimbursement starts with accurate mileage records, current fuel price data, and a consistent MPG assumption. But employers should also decide whether they are reimbursing only fuel or the broader cost of business vehicle use.
A fuel-only approach can leave gaps because business driving also creates fixed and variable vehicle costs. IRS Publication 463 lists actual car expenses such as gas, oil, tires, repairs, insurance, registration fees, depreciation, parking fees, and tolls.
Employers should review whether their reimbursement method accounts for:
A mileage reimbursement program, actual expense method, accountable allowance, or FAVR reimbursement may be more appropriate than adding a separate gas card or fuel reimbursement on top of an outdated program.
Divide the fuel price per gallon by the vehicle’s miles per gallon. For example, $5.50 per gallon divided by 22.5 MPG equals about $0.2444 per mile.
Mileage reimbursement often includes gas as one part of the rate, but it may also account for other vehicle costs such as maintenance, tires, insurance, depreciation, registration, taxes, repairs, parking, and tolls.
Not always. A fuel card may cover gas, but it usually does not cover the full cost of using a personal vehicle for work. Employers should review whether other business-use vehicle expenses are also being reimbursed.
MPG affects how much fuel an employee uses per mile. A lower-MPG vehicle has a higher fuel cost per mile than a higher-MPG vehicle when fuel prices are the same.
Some employers may use actual vehicle data, but others use a company-selected standard vehicle to create a consistent reimbursement methodology. The right approach depends on program goals, fairness, administration, and documentation.
FAVR may help because it separates fixed vehicle costs from variable operating costs. Fuel is usually treated as a variable cost, while expenses such as insurance, depreciation, taxes, and registration are fixed costs.
Not sure whether your reimbursement rate accurately accounts for fuel costs? mBurse can help you compare fuel cost per mile, mileage reimbursement, fuel cards, car allowances, mileage tracking, standard vehicle assumptions, and FAVR reimbursement options to identify where your program may be overpaying, underpaying, or creating unnecessary administrative work.