Metric vs. Imperial: What’s the Difference?

When we encounter measurements in our daily lives, whether it’s cooking, traveling, or buying produce, we often come across two distinct systems of measurement: metric vs. imperial. Understanding these systems is crucial because they are used for different purposes and in various regions around the world.

The Difference between Metric and Imperial

Metric vs. Imperial: Key Takeaways

Metric System

  • Base Units: Meter, liter, gram
  • Increments: Multiples of 10

Imperial System

  • Base Units: Inch, foot, yard, mile, ounce, pound, pint, gallon
  • Increments: Varied, such as 12 inches in a foot, 3 feet in a yard
Metric vs. Imperial
Metric vs. Imperial – Created by 7ESL

Metric vs. Imperial: the Definition

What Does Metric Mean? 

The Metric system is an international decimalized system of measurement, based on the meter, kilogram, and second. It’s used for a variety of measurements such as length, mass, and volume. Examples of metric units include:

  • Length: meter (m), centimeter (cm), kilometer (km)
  • Mass: kilogram (kg), gram (g)
  • Volume: liter (L), milliliter (mL)

Here’s a simple table to illustrate common metric conversions:

Unit Equals
1 meter 100 centimeters
1 kilogram 1,000 grams
1 liter 1,000 milliliters

What Does Imperial Mean? 

The Imperial system, or British Imperial, is a system of weights and measures that was officially used in Great Britain from 1824 until the adoption of the metric system. It utilizes units like inches, pounds, and gallons. Examples of Imperial units include:

  • Length: inch (in), foot (ft), mile (mi)
  • Weight: pound (lb), stone (st)
  • Volume: pint (pt), gallon (gal)

Here’s how some Imperial units translate:

Unit Equals
1 inch 2.54 centimeters
1 pound 0.4536 kilograms
1 gallon 4.54609 liters (UK)

While most countries have transitioned to the Metric system, the Imperial system is still used in some countries, including the United States, for various applications.

Tips to Remember the Difference

To keep the two systems straight, consider the metric system’s uniformity — it’s always in tens. Contrast this with the imperial system, where units don’t follow a single conversion base, such as 12 inches to a foot or 16 ounces to a pound.

Metric vs. Imperial: Examples

Example Sentences Using Metric

  • For length: We usually measure our running track in meters, so it’s about 400 meters around for one lap.
  • For mass: When we buy flour for baking, we often get a 1-kilogram bag from the store.
  • For volume: We filled our water bottle with 500 milliliters of water before our hike.
  • For temperature: On a hot day, we might say it’s 35 degrees Celsius outside.
  • For speed: We notice that the speed limit is typically around 120 kilometers per hour on many European highways.

Example Sentences Using Imperial

  • For length: We measure the height of a person in feet and inches; my cousin is 5 feet 10 inches tall.
  • For mass: When we weigh ourselves, we might find that we are 140 pounds.
  • For volume: We usually buy milk in gallons, so a common size is one gallon of milk.
  • For temperature: We might discuss the weather by saying it’s 75 degrees Fahrenheit today.
  • For speed: On the highway, we observe that speed limits are often posted in miles per hour, commonly 65 mph.

Related Confused Words

Metric vs. Standard

Metric refers to the international decimal system of measurement, which is based on multiples of ten. It includes units like meters, liters, and grams. However, in the United States, the term “Standard” is often used interchangeably with “Imperial”, but it’s a misnomer. Technically, “Standard” should relate to the widely accepted and used system within a given region. So for the U.S., “Standard” might be understood as referring to American customary units, which are derived from the British imperial system but have some differences.

Metric Standard
Meter Yard
Liter Gallon
Gram Ounce/Pound

Imperial vs. Customary

The Imperial system is a collection of units first defined in the British Weights and Measures Act of 1824. It includes pounds for weight, gallons for volume, and yards for distance. On the other hand, Customary units are the system of measurements commonly used in the United States, which, while similar to Imperial, differ in amounts. For instance, a gallon in the U.S. is smaller than the British Imperial gallon.

Imperial U.S. Customary
Imperial gallon U.S. gallon
Pound Pound (same name, same unit as Imperial)
Yard Yard (same as Imperial)

Through these distinctions, we can see that while these terms are often confused, they refer to different systems or units, and using the correct term can help us avoid misunderstandings.