Fuel Economy Calculator

Calculate your vehicle's fuel efficiency, estimate fuel costs, plan trip expenses, and compare different vehicles to make informed decisions about fuel economy.

Vehicle Information

Measurement Unit

Distance Traveled (miles) *

Fuel Used (gallons) *

Fuel Price ($ per gallon) *

Optional Analysis

Annual miles DrivenFor annual cost calculation

Trip Distance (miles)For trip cost estimation

Compare with MPGFor vehicle comparison

Vehicle Price Difference ($)For payback period calculation

Fuel Economy Results

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Enter your vehicle's distance and fuel usage to calculate fuel economy

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MPG Calculation

Calculate precise fuel efficiency in multiple units (MPG, L/100km, km/L)

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Cost Analysis

Calculate fuel costs per mile, annual expenses, and trip planning

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Vehicle Comparison

Compare different vehicles and calculate potential savings and payback periods

Fuel Economy Calculator FAQ

Get answers to common questions about fuel economy calculator

ℹ️ What is Fuel Economy Calculator?

A fuel economy calculator measures how efficiently a vehicle uses fuel — in miles per gallon (MPG) or liters per 100km. It helps estimate fuel costs for trips, compare vehicle efficiency, and track whether your actual fuel efficiency matches manufacturer claims.

📐 Formula

MPG = Miles Driven / Gallons Used | Cost = (Miles / MPG) × Price per Gallon

Miles Driven— Total distance of the trip or fill-up cycle

Gallons Used— Fuel consumed (difference between fill-ups)

L/100km— Metric: Litres ÷ (Distance/100)

✏️ Worked Example

Miles Driven: 350 miles

Gallons Used: 12 gallons

Gas Price: $3.50/gallon

1MPG = 350 / 12 = 29.2 mpg
2Cost per mile = $3.50 / 29.2 = $0.12/mile
3Total trip cost = $3.50 × 12 = $42.00

✅ Result: Fuel Economy = 29.2 MPG | Trip cost = $42.00

💡 How to Interpret Results

▸Higher MPG = better fuel economy = lower cost per mile.
▸City MPG is typically 20–30% lower than highway MPG due to stop-and-go driving.
▸Compare your actual MPG to the EPA estimate — if significantly lower, check tire pressure, air filter, and driving habits.
▸Electric vehicle equivalent: MPGe (miles per gallon equivalent, based on 33.7 kWh = 1 gallon of gasoline energy).
▸For long road trips, improved aerodynamics (cruise control, reduced drag) can improve MPG by 5–15%.