Span to Cable Length Conversion Calculator: Free Online Tool
Convert spans to cable lengths with our free online length converter.
Span to Cable Length Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Span).
- The converted value in Cable Length will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Span to Cable Length
Converting Span to Cable Length involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Span = 0.00123434 cable lengthsExample Calculation:
Convert 10 spans: 10 × 0.00123434 = 0.0123434 cable lengths
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Span and a Cable Length?
The Span is an ancient unit of length based on the distance across an outstretched human hand, measured from the tip of the thumb to the tip of the little finger (or sometimes the index finger). As an anthropomorphic unit, its length was inherently variable, depending on the size of an individual's hand.
Historically, it was often defined in relation to other body-based units:
- Typically considered half a cubit.
- Often equated to 3 palms (where a palm is the width of the hand across the base of the fingers).
- Sometimes defined as 12 digits (fingerbreadths).
A common, though unofficial, modern estimate for a span is around 9 inches or approximately 22.86 centimeters (cm).
A Cable Length (symbol cb), often shortened to cable, is a nautical unit of length, traditionally related to the length of a ship's anchor cable. While its exact length has varied historically and geographically, it is now most commonly defined internationally as one-tenth of a nautical mile (1/10 NM).
This standard definition equates to:
- 185.2 meters (m)
- Approximately 607.61 feet (ft)
- Approximately 202.54 yards (yd)
Other historical definitions based on the fathom also exist.
Note: The Span is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Cable Length belongs to the imperial/US customary system.
History of the Span and Cable Length
The span is one of the oldest informal units of measurement, used by numerous ancient civilizations, including the Egyptians, Israelites, Greeks, and Romans, due to the convenience of using the human hand.
- Ancient Egypt & Mesopotamia: The span was used alongside the cubit and digit. The relationship (often 1 span = 1/2 cubit) was fundamental in their systems.
- Biblical References: The span is mentioned in the Bible (e.g., Exodus 28:16 describing the High Priest's breastplate, Goliath's height in some interpretations).
- Ancient Greece & Rome: Used as a practical subdivision of the cubit.
- Medieval Europe: Continued in informal use and sometimes appeared in texts defining lengths. In England, it was often standardized (unofficially) as 9 inches.
Like other anthropomorphic units, the span fell out of official use with the development and adoption of more standardized systems like the Imperial (inches, feet) and Metric (meters) systems, which provided necessary precision for trade, science, and industry.
The unit originated from the practical length of a ship's anchor cable (or "shot" of chain) used in the age of sail. Anchor cables were typically manufactured in standard lengths that could be shackled together. This length provided a convenient unit for measuring distances related to anchoring and maneuvering close to shore or other vessels.
However, the length was not universally standardized:
- In the British Royal Navy, a cable was traditionally defined as 100 fathoms (equivalent to 600 feet or 182.88 meters).
- In the U.S. Navy, it was often defined as 120 fathoms (equivalent to 720 feet or 219.456 meters).
With the international adoption of the nautical mile (defined as 1852 meters), defining the cable as exactly one-tenth of this value (185.2 m) created a convenient, decimal-based relationship and became the most common modern standard, sometimes referred to as the "international cable length".
Common Uses for spans and cable lengths
Explore the typical applications for both Span (imperial/US) and Cable Length (imperial/US) to understand their common contexts.
Common Uses for spans
The span is now obsolete for precise or official measurements but is still encountered or used in specific contexts:
- Informal Estimation: Used for quick, rough measurements of moderate lengths where precision is not critical (e.g., gardening, crafts, estimating object sizes).
- Historical Texts: Found in ancient and medieval documents, requiring understanding for interpretation.
- Anthropology & Archaeology: Relevant when studying historical measurement systems or interpreting dimensions from ancient sites.
- Figurative Language: Can be used metaphorically to denote a small distance or extent ("life span").
- Understanding Historical Units: Key to grasping the relationship between units like the digit, palm, and cubit in ancient systems.
Common Uses for cable lengths
The cable length, particularly the 1/10 NM definition, remains in use in specific maritime contexts:
- Nautical Navigation & Ship Handling: Measuring short distances at sea, such as the distance between ships in formation, distance off a navigational hazard, distance to a pier, estimating anchor drag, or describing the scope (length) of anchor cable paid out.
- Hydrographic Surveying: Historically used on nautical charts, although meters are now the primary international standard for depth and short distances on modern charts.
- Naval Terminology: Persists in naval traditions and communications for describing close ranges.
- Historical Context: Encountered in older maritime texts, logs, charts, and naval records.
Frequently Asked Questions
Questions About Span (span)
How long is a span?
There is no single, universally fixed length for a span because it's based on human hand size. However:
- A common historical and modern estimate is 9 inches (in).
- This is approximately 22.86 centimeters (cm) or 0.2286 meters (m).
- Historically, it was often defined as half a cubit, which varied (e.g., a common cubit of ~18 inches would yield a 9-inch span).
What is the relationship between a span and a cubit?
In many historical systems, a span was considered half (1/2) of a cubit. Since cubits themselves varied (e.g., common cubit vs. royal cubit), the exact length of the span derived this way also varied.
What is the relationship between a span and a palm or digit?
Common relationships, though varying by system, were:
- 1 span ≈ 3 palms (where a palm is the width of the hand).
- 1 span ≈ 12 digits (where a digit is the width of a finger).
Is the span an SI unit?
No, the span is not an SI unit. It is an ancient, non-standardized, anthropomorphic unit. The SI base unit for length is the meter (m).
Is the span still used today?
The span is not used for any official, scientific, or commercial measurements. Its use is limited to informal estimations, historical context, and figurative language. People might still use their own hand span for a quick size check.
Where does the name 'span' come from?
The word "span" comes from Old English spann, related to the verb spannan, meaning "to stretch, extend, or connect". This directly reflects the action of stretching the hand to measure the unit.
About Cable Length (cb)
What are the different values for a cable length?
The value depends on the definition being used:
- International Standard: 1 cable = 1/10 nautical mile = 185.2 meters ≈ 607.61 feet. (Most common modern definition)
- British Traditional: 1 cable = 100 fathoms = 182.88 meters = 600 feet.
- US Traditional: 1 cable = 120 fathoms = 219.456 meters = 720 feet.
Always clarify which definition is intended if precision is critical, though the 1/10 NM version is generally assumed today unless otherwise specified.
How many meters are in a standard cable length?
The internationally recognized standard cable length is exactly 185.2 meters.
How many feet are in a standard cable length?
The internationally recognized standard cable length is approximately 607.61 feet. The traditional British cable was 600 ft, and the traditional US cable was 720 ft.
Is the cable length related to the nautical mile?
Yes, the most common modern definition establishes a direct relationship: 1 cable length = 1/10 nautical mile.
Is the cable length an SI unit?
No, the cable length is not an SI unit. It is a traditional nautical unit derived from maritime practice and later linked to the nautical mile. The corresponding SI unit for length is the meter (m).
Is the cable length still used today?
Yes, while meters and nautical miles are standard for most navigation, the cable length (especially the 1/10 NM definition) is still actively used in specific maritime applications like anchoring, close maneuvering, naval operations, and sometimes in recreational boating contexts. It serves as a convenient subdivision of the nautical mile.
Conversion Table: Span to Cable Length
| Span (span) | Cable Length (cb) |
|---|---|
| 1 | 0.001 |
| 5 | 0.006 |
| 10 | 0.012 |
| 25 | 0.031 |
| 50 | 0.062 |
| 100 | 0.123 |
| 500 | 0.617 |
| 1,000 | 1.234 |
All Length Conversions
Other Units from Length
- Meter (m)
- Kilometer (km)
- Hectometer (hm)
- Decimeter (dm)
- Centimeter (cm)
- Millimeter (mm)
- Inch (in)
- Foot (ft)
- Yard (yd)
- Mile (mi)
- Nautical Mile (NM)
- Micrometer (μm)
- Nanometer (nm)
- Light Year (ly)
- Astronomical Unit (AU)
- Parsec (pc)
- Angstrom (Å)
- Point (Typography) (pt)
- Mil/Thou (mil)
- Fathom (fath)
- Furlong (fur)
- Link (Gunter's) (li)
- Pace (pace)
- Digit (digit)
- Ell (ell)
- Finger (finger)
- Roman Mile (m.p.)
- Stadion (stadion)
- Chi (Chinese) (chi)
- Shaku (Japanese) (shaku)
- Li (Chinese) (li)
- Toise (toise)
- Bolt (bolt)
- Rope (rope)
- Smoot (smoot)
- Sajene (sajene)
- Ken (ken)
- Wa (wa)
- Vara (vara)
- Aln (aln)
- Cubit (Royal/Egyptian) (cubit)
- Versta (versta)
- Arpent (arpent)
- Ri (Japanese) (ri)
- Klafter (klafter)
- Yojana (yojana)
- Skein (skein)