Calculator Comparison

Energy Converter vs Fuel Economy Converter

Not sure which calculator to use? Here's a side-by-side comparison of the Energy Converter and Fuel Economy Converter to help you pick the right one for your needs.

Energy Converter

Unit Conversions

Convert between common energy units including joules, calories, kilocalories, BTU, and kilowatt-hours.

What you enter

Energy Value
From Unit

What you get

Joules(primary)
Calories
Kilocalories
BTU
Kilowatt-hours

Use Energy Converter

Fuel Economy Converter

Unit Conversions

Convert between fuel economy and efficiency units including miles per gallon (MPG), liters per 100 kilometers, and kilometers per liter.

What you enter

Fuel Economy Value
From Unit

What you get

Miles per Gallon(primary)
Liters per 100 km
Kilometers per Liter

Use Fuel Economy Converter

Key Differences

Feature	Energy Converter	Fuel Economy Converter
Category	Unit Conversions	Unit Conversions
Inputs	2 required fields	2 required fields
Outputs	5 results	3 results
Chart	No chart	No chart
FAQs	3 answered	3 answered

Input Comparison

Shared Inputs

From Unit

Only in Energy Converter

Energy Value

Only in Fuel Economy Converter

Fuel Economy Value

Which Calculator Should You Use?

Use the Energy Converter if you need to:

Calculate joules
When you know your energy value and from unit

Use the Fuel Economy Converter if you need to:

Calculate miles per gallon
When you know your fuel economy value and from unit

Frequently Asked Questions

What is the difference between a calorie and a Calorie?

A lowercase calorie (cal) is the energy to raise 1 gram of water by 1°C. An uppercase Calorie (Cal, or kilocalorie) is 1,000 calories and is what food labels use. When a food label says 200 Calories, it means 200 kilocalories.

How much energy does a kWh represent?

One kilowatt-hour (kWh) is 3.6 million joules. It is the energy consumed by a 1,000-watt appliance running for one hour. The average US household uses about 30 kWh per day.

How do I convert MPG to liters per 100 km?

Divide 235.215 by the MPG value. For example, 25 MPG = 235.215 / 25 = 9.41 L/100km. The relationship is inverse: higher MPG means lower L/100km (better efficiency).

What is considered good fuel economy?

For gasoline cars, 30+ MPG (under 7.8 L/100km) is considered good. Hybrid vehicles typically get 40-60 MPG. The average new car in the US gets about 25-30 MPG combined.

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Bottom Line

Choose the Energy Converter if you need to calculate joules. Use the Fuel Economy Converter if you need to calculate miles per gallon. Both calculators are free and require no sign-up.

Use Energy Converter Use Fuel Economy Converter

Feature

Energy Converter

Fuel Economy Converter