Mileage Calculator
Calculate Mileage & Cost
Result
| Distance Driven | — |
|---|---|
| Fuel Economy | — |
| Total Fuel Cost | — |
| Cost per Unit Distance | — |
How to Use This Mileage Calculator
Fleet logs and expense reports live or die on consistent odometer math. I have seen one transposed digit on an end reading throw off an entire month's fuel economy. This tool takes start and end odometer values, the fuel you added, and pump price—then returns distance, economy, total fuel cost, and cost per mile or kilometer.
- Select Distance Unit. Choose miles or kilometers to match your odometer.
- Enter Start Odometer. Record the reading at the beginning of the segment—usually right after a fill-up.
- Enter End Odometer. Record the reading when you refuel or end the trip segment.
- Enter Fuel Added and Price. Type gallons or liters pumped and the price per unit from your receipt.
- Press Calculate. Review distance driven, fuel economy, total fuel cost, and cost per unit distance.
For economy from trip-meter distance without odometer subtraction, try the Gas Mileage Calculator. To estimate an upcoming drive's fuel spend from known MPG, use the Fuel Cost Calculator.
Mileage Formulas and Practical Applications
Your odometer is a rolling tape measure. Subtract start from end to get distance, then relate that to the fuel you bought on the same segment—like balancing a checkbook where gallons are the withdrawal and miles are what you purchased with them.
Distance Driven = End Odometer − Start Odometer
Fuel Economy = Distance Driven ÷ Fuel Added
Total Fuel Cost = Fuel Added × Fuel Price
Cost per mile (or km) divides total fuel cost by distance—handy for comparing routes, vehicles, or reimbursement rates. Example: odometer moves from 50,000 to 50,300 (300 miles), you pump 12 gallons at $3.50, economy is 25 MPG, total cost $42.00, and cost per mile is $0.14.
Standard Units and Conversion Tables
Match the distance unit to your odometer and the fuel unit to your pump receipt for the clearest economy label.
- Miles + US gallons: Economy displays as MPG—the US standard.
- Kilometers + liters: Economy displays as km/L with L/100km in parentheses.
- Mixed units: Economy shows as distance per fuel volume in your selected combination (e.g., miles per liter).
- Cost per unit distance: Dollars per mile when distance is miles; dollars per km when distance is kilometers.
Frequently Asked Questions
Why do I need both start and end odometer readings?
Subtracting start from end gives the exact distance for that fuel segment. Trip odometers get reset by accident; the main odometer is the reliable record for mileage logs and reimbursements.
How can I improve my overall mileage?
Keep tires properly inflated, drop unnecessary cargo, avoid hard acceleration, and stay near posted highway speeds. Regular maintenance—clean air filters, correct oil, healthy spark plugs—helps combustion efficiency.
What if my end odometer is lower than the start reading?
The calculator requires end odometer to exceed start odometer. Double-check for typos, or confirm the vehicle was not replaced mid-period if you are logging fleet data.
Can I use this for business mileage reimbursement?
Yes for quick segment math—distance, economy, and cost per mile or km. Keep receipts and a contemporaneous log; tax and employer rules vary and this tool does not replace official recordkeeping.
Why does fuel economy format change with my unit choices?
When distance is in miles and fuel in US gallons, results show MPG. When distance is kilometers and fuel is liters, results show km/L and L/100km. Mixed units display as distance per fuel volume in your selected units.