Automotive
Fuel Economy Calculator
Use our free Fuel Economy Calculator to calculate miles per gallon (MPG), kilometers per liter (KM/L), and fuel costs for your vehicle. Perfect for drivers and fleet management to track efficiency.
Why Track Fuel Economy?
Fuel is one of the largest ongoing vehicle expenses. Tracking your fuel economy helps you spot inefficiencies, compare vehicles, plan trip budgets, and save money over time. A drop in MPG can also signal maintenance issues like low tire pressure, dirty air filters, or engine problems.
This calculator computes your vehicle's efficiency in MPG, km/L, and L/100km — plus cost per 100 miles/km, cost per mile/km, and trip fuel cost estimates. Works for cars, trucks, motorcycles, and any fuel-powered vehicle.
How to Use This Calculator
- Select Imperial (miles/gallons) or Metric (km/liters)
- Enter distance traveled and fuel consumed
- Optionally enter fuel price for cost calculations
- Optionally enter trip distance for trip cost estimate
- Click Calculate Fuel Economy
Common Use Cases
- Track daily commute costs
- Compare vehicle efficiency
- Plan road trip budgets
- Fleet fuel management
- Detect maintenance issues
- New vs. old car comparison
Average Fuel Economy by Vehicle Type
| Vehicle Type | MPG (avg) | L/100km | km/L | Rating |
|---|---|---|---|---|
| Hybrid / Electric | 45–60+ | 3.9–5.2 | 19–25+ | Excellent |
| Compact Car | 30–40 | 5.9–7.8 | 12.8–17 | Good |
| Sedan / Midsize | 25–35 | 6.7–9.4 | 10.6–14.9 | Good |
| SUV / Crossover | 20–28 | 8.4–11.8 | 8.5–11.9 | Average |
| Pickup Truck | 15–22 | 10.7–15.7 | 6.4–9.4 | Average |
| Sports Car | 15–25 | 9.4–15.7 | 6.4–10.6 | Average |
| Heavy Truck / RV | 6–12 | 19.6–39.2 | 2.6–5.1 | Poor |
| Motorcycle | 40–70 | 3.4–5.9 | 17–30 | Excellent |
Fuel Economy Unit Conversions
| From | To | Formula |
|---|---|---|
| MPG | km/L | MPG × 0.4251 |
| MPG | L/100km | 235.215 ÷ MPG |
| km/L | MPG | km/L ÷ 0.4251 |
| km/L | L/100km | 100 ÷ km/L |
| L/100km | MPG | 235.215 ÷ L/100km |
| 1 US gallon | Liters | 3.785 liters |
| 1 mile | Kilometers | 1.609 km |
FAQ – Fuel Economy Calculator
What is a Fuel Economy Calculator?
A Fuel Economy Calculator determines your vehicle's fuel efficiency by calculating how far it travels per unit of fuel — measured in MPG (miles per gallon), km/L (kilometers per liter), or L/100km.
How do I calculate my car's MPG?
Fill your tank, reset the trip odometer, drive normally, then fill up again. Divide the miles driven by the gallons used. For example: 350 miles ÷ 12.5 gallons = 28 MPG.
What's the difference between MPG and L/100km?
MPG measures distance per fuel unit (higher is better). L/100km measures fuel per distance (lower is better). They're inversely related: 235.215 ÷ MPG = L/100km.
What factors affect fuel economy?
Driving speed, acceleration habits, tire pressure, vehicle weight, air conditioning, terrain, weather, engine condition, and fuel quality all impact fuel economy significantly.
How can I improve my fuel efficiency?
Maintain proper tire pressure, drive smoothly (avoid hard acceleration/braking), reduce idling, remove excess weight, use cruise control on highways, and keep up with regular maintenance.
What is considered good fuel economy?
For cars: 30+ MPG (7.8 L/100km or less) is good, 40+ MPG is excellent. For SUVs: 25+ MPG is good. For trucks: 20+ MPG is good. Hybrids typically achieve 45–60+ MPG.
Can I use this for motorcycles and trucks?
Yes. Enter the distance and fuel for any fuel-powered vehicle — cars, trucks, motorcycles, RVs, boats, or fleet vehicles. The calculation works the same way.
How does speed affect fuel economy?
Most vehicles are most efficient at 45–65 mph (70–105 km/h). Above 65 mph, fuel economy drops roughly 1–2% for every mph increase due to aerodynamic drag.
Does AC use more fuel?
Yes. Air conditioning can reduce fuel economy by 5–25% depending on conditions. At low speeds, open windows are more efficient. At highway speeds, AC is more efficient than open windows (which increase drag).
How accurate is this calculator?
It's as accurate as your inputs. For best results, fill your tank completely both times, use the trip odometer for distance, and note the exact gallons/liters pumped.