Convert Nail to Millimeter
Convert nails to millimeters instantly. 1 nail = 57.15 millimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Millimeter to Nail converter for the reverse conversion.
Units explained
Nail
A nail is an Imperial unit of length equal to 2.25 inches (about 57.15 mm). It was historically used in the English cloth trade.
The nail derives from an English cloth-measure tradition dating to medieval times. Standardised at 2.25 inches (or 1/16 of a yard) through English customary practice and ratified by the 1959 International Yard and Pound Agreement.
Nails were historically used to measure cloth, particularly small pieces and ribbons. Rare in modern commerce but appears in historical textile literature and reproduction crafts.
Medieval English cloth-trade origin; standardised at 1/16 yard; fixed exactly at 0.05715 m via the 1959 International Yard and Pound Agreement.
Millimeter
A millimeter is a metric unit of length equal to one thousandth of a meter (1/1000 m). It is the standard small-scale unit in the SI system and is widely used wherever sub-centimeter precision matters.
The millimeter was defined alongside the meter when France adopted the metric system in 1795, using the standard SI prefix milli- (from Latin mille, "thousand") to denote one-thousandth.
Millimeters are used in engineering drawings, machining, manufacturing, paper sizes, rainfall measurement, and any context where dimensions below one centimeter need to be specified clearly. Most rulers worldwide are marked in millimeters.
Adopted in 1795 in France as part of the original metric system; standardized internationally by the Metre Convention in 1875 and confirmed in the SI in 1960.
Nail to Millimeter conversion formula
The relationship between nails and millimeters:
To convert nails to millimeters, multiply the value in nails by 57.15. To reverse, multiply millimeters by 0.0174978128.
How to use this converter
Type a value into the calculator. The result in millimeters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Millimeter to Nail converter for the reverse direction.
Step-by-step: convert nails to millimeters
- Write down the value in nails (nail).
- Multiply that value by the factor 57.15.
- The product is the equivalent value in millimeters (mm).
- To reverse, multiply the millimeter value by 0.0174978128.
Worked examples
Example 1 — Convert 1 nail to mm:
1 × 57.15 = 57.15 mm
Example 2 — Convert 100 nail to mm:
100 × 57.15 = 5715 mm
Real-world example — Postcard and small-object dimensions
A postcard is about 5 nails wide. Converting to millimeters is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 nail × 57.15 = 285.75 mm
Real-world example — Ruler-scale measurements
A 30-nail school ruler converts cleanly to millimeters — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 nail × 57.15 = 1714.5 mm
Real-world example — Hardware-scale dimensions
A 10-nail fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between nails and millimeters daily when mixing metric and imperial tools.
10 nail × 57.15 = 571.5 mm
Nail to Millimeter conversion table
Standard reference values for converting nails to millimeters:
| Nail [nail] | Millimeter [mm] |
|---|---|
| 0.01 | 0.5715 |
| 0.1 | 5.715 |
| 1 | 57.15 |
| 2 | 114.3 |
| 3 | 171.45 |
| 4 | 228.6 |
| 5 | 285.75 |
| 10 | 571.5 |
| 20 | 1143 |
| 30 | 1714.5 |
| 40 | 2286 |
| 50 | 2857.5 |
| 100 | 5715 |
| 500 | 28575 |
| 1000 | 57150 |
Frequently asked questions
How many millimeters is 1 nail?
How do I convert nails to millimeters?
How do I convert millimeters back to nails?
How many millimeters is 100 nails?
Popular length unit conversions
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 nail = 57.15 mm) 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.