Convert Hand to Mil
Convert hands to mils instantly. 1 hand = 4000 mil — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Mil to Hand converter for the reverse conversion.
Units explained
Hand
A hand is an Imperial unit of length equal to 4 inches (101.6 mm). It is used primarily to measure the height of horses at the withers.
The hand derives from the average breadth of a human hand and was standardised at exactly 4 inches by the Statute of Henry VIII in 1541.
Hands are used worldwide for horse height specification (the typical riding horse is 14–17 hh). Also used in some equestrian-adjacent contexts. The unit is now almost exclusively a horse-measurement convention.
Standardised at 4 inches by Henry VIII in 1541; value became exact in 1959 when the inch was fixed at 25.4 mm.
Mil
A mil (also called a thou) is an Imperial unit of length equal to one thousandth of an inch (1/1000 in = 0.0254 mm = 25.4 μm exactly). It is used in engineering, manufacturing, and materials specifications.
The mil is derived from the Latin mille, "thousand," denoting one-thousandth of an inch. Standardized in industrial use during the 19th-century rise of precision engineering.
Mils are used to specify thicknesses of plastic films, foils, paper, copper traces on printed circuit boards (PCBs), wire insulation, and paint coatings. A standard sheet of paper is about 4 mils thick.
Adopted in 19th-century engineering practice; the value (1/1000 in) became exact in 1959 when the inch was fixed at 25.4 mm via the International Yard and Pound Agreement. The British term is "thou"; American term is "mil".
Hand to Mil conversion formula
The relationship between hands and mils:
To convert hands to mils, multiply the value in hands by 4000. To reverse, multiply mils by 0.00025.
How to use this converter
Type a value into the calculator. The result in mils updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Mil to Hand converter for the reverse direction.
Step-by-step: convert hands to mils
- Write down the value in hands (hh).
- Multiply that value by the factor 4000.
- The product is the equivalent value in mils (mil).
- To reverse, multiply the mil value by 0.00025.
Worked examples
Example 1 — Convert 1 hh to mil:
1 × 4000 = 4000 mil
Example 2 — Convert 100 hh to mil:
100 × 4000 = 399999.9999999999 mil
Real-world example — Macroscopic to microscopic
One hand equals a million mils. Optical engineers calculating coherence length compare macro-scale path lengths with micro-scale wavelength differences using exactly this conversion.
1 hh × 4000 = 4000 mil
Real-world example — Sub-meter precision
A 0.001-hand (1 mm) tolerance equals 1,000 mils — useful for surface-finish specs, where macro-scale dimensions are given in the larger unit but feature roughness in the smaller.
0.001 hh × 4000 = 4 mil
Real-world example — Macro-to-micro scale comparison
2 hands of measurement converts to a very large number in mils — useful in materials science when comparing bulk-sample dimensions to feature-level surface specs.
2 hh × 4000 = 8000 mil
Hand to Mil conversion table
Standard reference values for converting hands to mils:
| Hand [hh] | Mil [mil] |
|---|---|
| 0.01 | 40 |
| 0.1 | 400 |
| 1 | 4000 |
| 2 | 8000 |
| 3 | 12000 |
| 4 | 16000 |
| 5 | 20000 |
| 10 | 40000 |
| 20 | 80000 |
| 30 | 120000 |
| 40 | 160000 |
| 50 | 200000 |
| 100 | 399999.9999999999 |
| 500 | 1999999.9999999998 |
| 1000 | 3999999.9999999995 |
Frequently asked questions
How many mils is 1 hand?
How do I convert hands to mils?
How do I convert mils back to hands?
How many mils is 100 hands?
Popular length unit conversions
Convert Hand to other length units
Show all Hand conversions
Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 hh = 4000 mil) 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 Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.