Span to Smoot Conversion Calculator: Free Online Tool
Convert spans to smoots with our free online length converter.
Span to Smoot Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Span).
- The converted value in Smoot 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 Smoot
Converting Span to Smoot involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Span = 0.134328 smootsExample Calculation:
Convert 10 spans: 10 × 0.134328 = 1.343284 smoots
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 Smoot?
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).
The Smoot is a non-standard, humorous unit of length created as part of an MIT fraternity prank in October 1958. It is defined by the height of Oliver R. Smoot (MIT class of 1962) at the time of the prank, which was 5 feet 7 inches.
This equates to:
- 67 inches (in)
- 1.7018 meters (m)
- Approximately 1.86 yards (yd)
Unlike standardized units, the Smoot is intrinsically tied to a specific individual's height at a particular moment and serves primarily as a cultural artifact and inside joke, particularly within the MIT community.
Note: The Span is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Smoot belongs to the imperial/US customary system.
History of the Span and Smoot
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 Smoot unit originated in October 1958 during the pledge activities of the Lambda Chi Alpha fraternity at MIT. Pledges were tasked with measuring the length of the Harvard Bridge, which connects Boston and Cambridge, Massachusetts, over the Charles River.
Instead of using conventional measuring tools, the fraternity members decided to use one of their pledges, Oliver Smoot, as the unit of measure. They repeatedly laid him down end-to-end across the bridge, marking off increments in paint. His companions carried him or helped him move for each new measurement.
The final measurement determined the bridge's length to be 364.4 Smoots "plus or minus one ear". The "ear" indicated the uncertainty of the measurement, adding to the absurdity and humor of the event.
The painted markings on the bridge became a local landmark. They have been maintained and periodically repainted over the decades, often unofficially by members of the fraternity or other MIT affiliates. The Cambridge Police Department traditionally tolerates the markings because, among other reasons, they serve as useful reference points for identifying locations along the bridge.
Interestingly, Oliver R. Smoot later became a prominent figure in standards organizations, serving as Chairman of the American National Standards Institute (ANSI) and President of the International Organization for Standardization (ISO), an ironic twist given his namesake unit's non-standard nature.
Common Uses for spans and smoots
Explore the typical applications for both Span (imperial/US) and Smoot (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 smoots
The Smoot is not used for any official, scientific, or commercial measurements. Its use is primarily cultural and humorous:
- Harvard Bridge Markings: The painted markings on the bridge sidewalk are its most famous application, indicating distance in Smoots from the Boston side. They are a well-known local landmark.
- MIT Culture and Slang: Used humorously within the MIT community and sometimes in the broader Boston area as a quirky local reference.
- Digital Recognition: The unit gained wider recognition when it was included as a unit of measurement in Google Calculator and Google Earth's ruler tool.
- Popular Culture: Occasionally referenced in media or tech circles as an example of a non-standard or humorous unit.
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 Smoot (smoot)
How long is a Smoot?
One Smoot is exactly the height of Oliver R. Smoot in 1958:
- 5 feet 7 inches
- 67 inches
- 1.7018 meters
Is the Smoot an official or standardized unit?
No, the Smoot is not an official or standardized unit of measurement in any system (Imperial, US customary, or SI). It is a non-standard, humorous unit originating from a specific event.
Why is the bridge measurement "plus or minus one ear"?
The "plus or minus one ear" (often written as ± εar) reflects the humorous imprecision of the original measurement method using a person. It signifies the margin of error in a whimsical way, possibly referencing the difficulty of the final partial measurement or simply adding to the prank's absurdity.
Are the Smoot markings still on the Harvard Bridge?
Yes, the markings are traditionally repainted periodically (often by Lambda Chi Alpha members) and are considered a fixture of the bridge. During bridge renovations in 2011, the Massachusetts Department of Transportation restored the markings, acknowledging their cultural significance.
How does the Smoot compare to standard units?
- 1 Smoot = 1.7018 meters
- 1 Meter ≈ 0.5876 Smoots
- 1 Smoot = 5.583 feet (5 feet 7 inches)
- 1 Foot ≈ 0.1791 Smoots
Is the Smoot an SI unit?
No, the Smoot is not an SI unit. It is a non-standard, informal unit. The SI base unit for length is the meter (m).
What did Oliver Smoot think of the unit?
Oliver Smoot generally embraced his namesake unit with good humor throughout his life and career, often participating in events related to it at MIT.
Conversion Table: Span to Smoot
| Span (span) | Smoot (smoot) |
|---|---|
| 1 | 0.134 |
| 5 | 0.672 |
| 10 | 1.343 |
| 25 | 3.358 |
| 50 | 6.716 |
| 100 | 13.433 |
| 500 | 67.164 |
| 1,000 | 134.328 |
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)
- Cable Length (cb)
- 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)
- 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)