MPG Calculator Guide
An MPG calculator computes miles per gallon from distance and fuel used. It can convert to L/100 km and compute cost per mile when you add fuel price.
What is MPG Calculator?
The MPG calculator helps drivers track efficiency and costs across fill-ups, routes, or vehicles. Enter miles and gallons (or km and liters), and the tool returns MPG, L/100 km, and optional cost metrics.
How to Use the MPG Calculator
- Enter distance driven and fuel used.
- Calculate MPG and see the L/100 km conversion.
- (Optional) enter fuel price to get total cost and cost per mile/km.
- Log results across trips to compare routes and habits.
- Tune driving (speed, tire pressure) to improve MPG.
Formulas & Methods
- MPG:
MPG = miles / gallons - L/100 km:
= 235.215 / MPG(US gallon) - Cost:
Total = gallons * price_per_gal;Cost per mile = Total / miles
Assumptions & limitations
- Use US gallons for 235.215 constant; imperial gallon uses a different factor.
- Short trips and cold starts lower MPG due to warm-up losses.
Examples
Example A — US units
Miles 360, Gallons 12 → MPG = 30. L/100 km = 235.215/30 = 7.84.
Example B — With cost
Price $3.90/gal: Total = 12*3.90 = $46.80; Cost/mile = 46.80/360 = $0.13.
| Input | Value | |---|---| | Miles | 360 | | Gallons | 12 | | MPG | 30 | | L/100 km | 7.84 |
Pro Tips & Best Practices
- Keep tires at recommended pressure.
- Remove roof racks and excess weight.
- Drive steadily; avoid hard accelerations and high speeds.
- Use trip averaging to smooth noisy single-tank results.
Related Calculators
FAQ
Q: How is MPG calculated?
A: MPG = miles driven / gallons used. For metric, L/100 km = 235.215 / MPG (US gallon).
Q: What is a good MPG?
A: Depends on vehicle type and driving; higher MPG means better efficiency. For EVs, use Wh/mi or MPGe.
Q: How do I track MPG accurately?
A: Fill to first click each time, reset trip odometer, and record gallons added; average over multiple tanks.
Q: Why does MPG vary?
A: Speed, traffic, temperature, AC, tires, load, and route profile all influence fuel use.
Q: Can I estimate cost per mile?
A: Yes—multiply gallons by price to get trip cost and divide by miles for cost per mile.
Call to Action
Enter miles and gallons to get MPG and cost—track across trips to see which habits and routes save the most.