What Is Span?
A span is an old unit of length based on the size of a human hand. It measures the distance from the tip of the thumb to the tip of the little finger when the hand is fully stretched. A span is usually taken as about 9 inches or about 23 centimeters, but it is not exact.
Definition
A span is a traditional unit used to measure short lengths. It is a body based unit because it comes from the human hand. Since different people have different hand sizes, the span is only an approximate measure.
In many historical systems a span was defined as:
- About half of a cubit
- About 9 inches
- About 22.9 centimeters
Modern science does not use the span as an official unit. Today we only use it to understand old texts, old buildings, or traditional crafts.
History / Origin
The idea of the span is very old. People have used body parts to measure things for thousands of years, long before rulers and tape measures existed. Hands and arms were always with you, so they were simple tools for measuring.
In many ancient cultures a span was used in building, farming, and trade. For example, in the ancient Middle East a span was taken as half of a cubit. Religious and historical writings from that region often use the word span when describing the size of objects or buildings.
Over time, as more accurate tools and standard units appeared, like the meter and the foot, the span slowly disappeared from official use. It stayed mainly in everyday speech and in some local building or craft traditions.
Symbol & Abbreviation
The span does not have a fixed official symbol in modern standards. In most texts it is simply written as the full word span.
Sometimes people use short forms, for example:
- sp as an informal abbreviation
- Just writing the word span after a number, for example 3 span
Because the span is not an SI unit and not part of most legal measurement systems today, you will not often see it in technical documents or engineering work.
Current Use Around the World
Today the span is rarely used in everyday measurement. However, it still appears in a few ways around the world.
- Historical studies People who study ancient texts, old buildings, and archaeology use the span to understand original sizes.
- Religious contexts Some religious writings mention spans, so teachers often explain what a span means in modern units.
- Traditional crafts In a few places craftsmen such as carpenters or weavers still use hand spans for quick, rough measurements.
- Everyday speech People may say something is about a span long when they only need a rough idea, not an exact number.
In modern law and trade, the span is almost never used. Instead, countries use metric units like centimeters and meters or imperial units like inches and feet.
Example Conversions
Because hand sizes differ, a span is only approximate. A common modern value is:
- 1 span ≈ 9 inches
- 1 span ≈ 22.9 centimeters
- 1 span ≈ 0.229 meters
| Span | Inches | Centimeters | Meters |
|---|---|---|---|
| 1 span | ≈ 9 in | ≈ 22.9 cm | ≈ 0.229 m |
| 2 spans | ≈ 18 in | ≈ 45.7 cm | ≈ 0.457 m |
| 3 spans | ≈ 27 in | ≈ 68.6 cm | ≈ 0.686 m |
| 4 spans | ≈ 36 in | ≈ 91.4 cm | ≈ 0.914 m |
You can use these simple rules for a quick estimate:
- To change spans to inches, multiply by 9.
- To change spans to centimeters, multiply by about 23.
Remember, these are only close values, not exact.
Related Units
The span is part of a family of body based length units. Some closely related units are:
- Cubit The length from the elbow to the tip of the middle finger. In many systems 1 cubit is about 2 spans.
- Hand A unit based on the width of the hand. In horse height, 1 hand is fixed as 4 inches. A span is longer than a hand because the fingers are stretched out.
- Palm Often the width of the four fingers held together, smaller than a span.
- Foot A traditional unit based on the length of a human foot. In modern use 1 foot is exactly 12 inches, which is a bit longer than a span.
- Inch A standard small unit. A span is usually taken as about 9 inches.
- Meter and centimeter Modern metric units. These are used today to give exact values for old units like the span.
FAQs
Q. What is a span in simple words?
A span is the distance across a fully stretched hand from the tip of the thumb to the tip of the little finger. It is an old way to measure length.
Q. How long is a span in inches?
A span is usually taken as about 9 inches. This is only a common average, not a strict rule.
Q. How many centimeters are in a span?
One span is often treated as about 23 centimeters. A more exact common value is 22.9 centimeters, but real hands are different sizes.
Q. Is a span the same as a hand?
No. A span is larger. A hand used in horse height is fixed at 4 inches. A span is about 9 inches. A span uses the full stretch of the hand, thumb to little finger.
Q. Why is the span not used in science today?
The span is based on body size, which changes from person to person. Science and engineering need exact and repeatable units, such as the meter and the inch, so the span is no longer used officially.
Q. Can I still use spans to measure things?
You can use spans for a quick rough measure in daily life, for example to guess if something will fit on a shelf. But for school, science, building, or shopping, always use standard units like centimeters, meters, inches, or feet.
Q. Is a span always exactly half a cubit?
In many old systems one span was treated as about half a cubit, but different places had different exact values. It is safer to think of the span as an approximate half cubit, not an exact one.