Length Measurement

 Length is the distance between two points and the measurement unit is 'meter' (or 'metre').

Meter ( Metre )

It is a unit of length measurement, other units are either submultiples or multiples of the meter, for example, centimeter.

The length of the guitar is approximately 1 meter.

A classroom door with a width of 1 meter and a height of 2 meters.

Kilometer  "km" ( Kilometre ) -1000 meter -

The word "kilo" has its origins in Greek. It is derived from the Greek word "χίλιοι" (khilioi), which means "thousand." This prefix is used in many units in the metric system (e.g., kilogram, kilometer) to denote a factor of one thousand.

Kilo Gram  --- Thousand Gram 
Kilo Meter --- Thousand Meter

Symbol : km

Since it is a large unit of length, it is generally used to measure distances between two settlements, like between cities or countries.

The distance between Paris and London is approximately 470 km.

A full lap of an athletics track." (A standard athletics track is 400 meters in length, so 2.5 full laps amount to approximately 1 kilometer.)

Hectometer "hm" ( Hectometre ) - 100 meter - 

Equal to 100 meters. The term "hecto-" is derived from the Greek word "ἑκατόν" (hekaton), which means "hundred." Therefore, a hectometer represents a hundred meters. Its symbol is "hm."

Hecto - Hundred 
meter - meter 
Symbol : hm

However, the hectometer is not as commonly used as other metric units like the meter, kilometer, or centimeter in everyday measurements.

For instance, the same term appears in land area measurements:

"Are" and its 100-fold, "Hectare". (An "Are" covers an area of 100 square meters, and a "Hectare" is 100 times that, which is 100 square meters * 100 = 10,000 square meters, equivalent to 10 acres.)

Are - 
Hectare  -- 100 times Are

The length of a football field." (The standard length of a football field typically ranges between 100 to 110 meters.)

Decameter "dam"( Decametre ) - 10 meter -

Equal to 10 meters. The prefix "deca-" comes from the Greek word "δέκα" (déka), which means "ten." Therefore, a decameter represents ten meters. Its symbol is "dam."

Deca --- Ten 

Decameter --- Ten meter

Symbol : dam

People trying to rescue a whale that's close to 10 meters in length.

Many bus models have a length ranging between 9 to 12 meters.)

Decimeter "dm"( Decimetre )  1/10 meter

Equal to one-tenth of a meter. The prefix "deci-" comes from the Latin word "decimus", which means "tenth." Therefore, a decimeter represents one-tenth of a meter. Its symbol is "dm."

Deci --- Tenth 

meter -- meter 

Symbol : dm

The width of our hand is approximately 1 decimeter.

The length of a smartphone is approximately between 10 cm and 15 cm.

Centimeter "cm" ( Centimetre ) 1/100 meter

Equal to one-hundredth of a meter. The prefix "centi-" comes from the Latin word "centum", which means "hundred." Therefore, a centimeter represents one-hundredth of a meter. Its symbol is "cm."

Cent -- 1/100
centimeter -- 1/100 of meter 
Symbol : cm

Cent - 1/100 of Euro or Dollar

The centimeter is commonly used in everyday measurements, especially for objects of a relatively small size, such as the dimensions of books, the height of a person, or the size of electronic devices.

Credit Card: About 8.5 cm x 5.4 cm.
A4 Paper: 21 cm x 29.7 cm.
Standard Ruler: Typically 30 cm in length.
Pencil: Usually around 15 cm to 20 cm long.
Average Adult Hand Width: Roughly 7 cm to 10 cm.
Book Spine: Varies, but many are around 2 cm to 5 cm thick.
Smartphone: Varies by model, but many are between 13 cm to 16 cm in length.
Shoe (Adult Size): Length varies widely, but the width might be around 10 cm for many adult sizes.
Compact Disc (CD): Diameter is 12 cm.
Wristwatch Face: Varies, but many are between 3 cm to 5 cm in diameter.

Milimeter "mm" ( Milimetre ) 1/1000 meter

Equal to one-thousandth of a meter. The prefix "milli-" comes from the Latin word "mille", which means "thousand." Therefore, a millimeter represents one-thousandth of a meter. Its symbol is "mm."

The millimeter is commonly used in everyday measurements, especially in contexts where precision is required. For example, it's often used in engineering, science, and medicine. Common objects like the thickness of a credit card (roughly 0.76 mm) or the diameter of a small raindrop (around 1 mm to 2 mm) can be measured in millimeters.

Grain of Rice: Roughly 5 mm to 7 mm in length.


Credit Card Thickness: About 0.76 mm.
Human Hair Diameter: Typically between 50 to 100 micrometers (0.05 mm to 0.1 mm).
Standard Pencil Lead: For a mechanical pencil, it can be 0.5 mm, 0.7 mm, or 0.9 mm.
Small Raindrop: Approximately 1 mm to 2 mm in diameter.
Grain of Rice: Roughly 5 mm to 7 mm in length.
Standard Paper Thickness: Often around 0.1 mm.
CD or DVD Thickness: About 1.2 mm.
Glasses Lens Thickness: Varies, but can be between 1 mm to 5 mm or more, depending on the prescription and material.
A Matchstick's Diameter: Approximately 2 mm to 3 mm.
Thickness of a Coin: Varies by coin, but many are between 1 mm to 3 mm.

What is more ?

Measurement Index 

Geometry Index