Convert X-unit to Yard
Convert x-units to yards instantly. 1 x-unit = 1.09591e-13 yard — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Yard to X-unit converter for the reverse conversion.
Units explained
X-unit
The X-unit (or siegbahn) is a historical X-ray crystallography unit of approximately 1.0021×10⁻¹³ meters. It was used before X-ray wavelengths could be measured directly in meters.
Introduced by Manne Siegbahn in 1925 as a self-consistent unit for X-ray crystallography. The 'X-unit' was defined to make the X-ray wavelength of the molybdenum K-alpha line a round number.
X-units appear in X-ray crystallography literature from 1925 through the 1960s. Modern crystallography uses meters or angstroms; X-units are mostly of historical interest now.
Defined by Manne Siegbahn in 1925; superseded by direct SI measurement of X-ray wavelengths after the 1960s; retained in literature for historical comparison.
Yard
A yard is an Imperial and US customary unit of length equal to 3 feet or exactly 0.9144 meters. It is used for medium distances, particularly in athletics and fabric/textile measurement.
The yard's origin is contested but traditionally attributed to the length from the tip of King Henry I's nose to the end of his outstretched thumb. It was standardized in English law from the medieval period and definitively fixed at 0.9144 m exactly by the 1959 International Yard and Pound Agreement.
Yards are used in American football (10 yards for a first down), golf course distances, fabric and carpet sales in the US, and short-distance running events. The UK uses yards informally and on road signs for short distances.
Standardized in English law from the Middle Ages; fixed at 0.9144 m exactly by the 1959 International Yard and Pound Agreement.
X-unit to Yard conversion formula
The relationship between x-units and yards:
To convert x-units to yards, multiply the value in x-units by 1.09591e-13. To reverse, multiply yards by 9.124838e+12.
How to use this converter
Type a value into the calculator. The result in yards updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Yard to X-unit converter for the reverse direction.
Step-by-step: convert x-units to yards
- Write down the value in x-units (X).
- Multiply that value by the factor 1.09591e-13.
- The product is the equivalent value in yards (yd).
- To reverse, multiply the yard value by 9.124838e+12.
Worked examples
Example 1 — Convert 1 X to yd:
1 × 1.09591e-13 = 1.09591e-13 yd
Example 2 — Convert 100 X to yd:
100 × 1.09591e-13 = 1.09591e-11 yd
Real-world example — From sub-micron to human scale
One billion x-units equals one yard — the conversion that drives home the gulf between atomic-scale features and everyday objects in physics curricula.
1e+9 X × 1.09591e-13 = 0.000109591 yd
Real-world example — Bridging nine orders of magnitude
500 million x-units equals a value comfortably in the human-scale yards range. Physics problems that span this gap are common when comparing the wavelength of light to the path length of an experiment.
5e+8 X × 1.09591e-13 = 5.479549e-5 yd
X-unit to Yard conversion table
Standard reference values for converting x-units to yards:
| X-unit [X] | Yard [yd] |
|---|---|
| 0.01 | 1.09591e-15 |
| 0.1 | 1.09591e-14 |
| 1 | 1.09591e-13 |
| 2 | 2.19182e-13 |
| 3 | 3.28773e-13 |
| 4 | 4.38364e-13 |
| 5 | 5.479549e-13 |
| 10 | 1.09591e-12 |
| 20 | 2.19182e-12 |
| 30 | 3.28773e-12 |
| 40 | 4.38364e-12 |
| 50 | 5.479549e-12 |
| 100 | 1.09591e-11 |
| 500 | 5.479549e-11 |
| 1000 | 1.09591e-10 |
Frequently asked questions
How many yards is 1 x-unit?
How do I convert x-units to yards?
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How many yards is 100 x-units?
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Metric / SI (4 units)
Imperial / US Customary (4 units)
Sources & references
Conversion factor (1 X = 1.09591e-13 yd) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.