Convert Square Millimeter to Are
Convert square millimeters to ares instantly. 1 square millimeter = 1e-8 are — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Are to Square Millimeter converter for the reverse conversion.
Units explained
Square Millimeter
A square millimeter is a metric unit of area equal to 10⁻⁶ m² (1 mm × 1 mm). It is widely used in engineering, electronics, and small-scale technical work.
Derived by squaring the millimeter, defined as 1/1000 of a meter. The milli- prefix comes from the Latin 'mille' (thousand).
Square millimeters express PCB trace cross-sections, the area of small mechanical features in CAD drawings, biological sample sizes, and material thicknesses.
Millimeter has been part of the metric system since 1795.
Are
An are is a metric unit of area equal to 100 square meters. It is used in some European countries for land measurement, especially for smaller plots like vineyards and gardens.
Introduced as part of the French metric system in 1795. The name comes from the Latin 'area' meaning surface or open ground.
Ares are still used in some European countries (especially Switzerland and France) for small-plot land measurement. In Switzerland, an are is a common unit for vineyard size. Most modern contexts prefer square meters or hectares.
Defined in 1795 in France as part of the original metric system.
Square Millimeter to Are conversion formula
The relationship between square millimeters and ares:
To convert square millimeters to ares, multiply the value in square millimeters by 1e-8. To reverse, multiply ares by 1e+8.
How to use this converter
Type a value into the calculator. The result in ares updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Are to Square Millimeter converter for the reverse direction.
Step-by-step: convert square millimeters to ares
- Write down the value in square millimeters (mm²).
- Multiply that value by the factor 1e-8.
- The product is the equivalent value in ares (a).
- To reverse, multiply the are value by 1e+8.
Worked examples
Example 1 — Convert 1 mm² to a:
1 × 1e-8 = 1e-8 a
Example 2 — Convert 100 mm² to a:
100 × 1e-8 = 1e-6 a
Real-world example — Paper and film thicknesses
At the thickness of office paper (roughly 3 square millimeters), converting between sub-millimeter units is routine for packaging and printing buyers comparing quotes from metric and US suppliers.
3 mm² × 1e-8 = 3e-8 a
Real-world example — Plastic-film thickness alternates
A 150-square millimeter plastic film converts cleanly to ares — useful for packaging buyers reconciling supplier datasheets across metric and US measurement systems.
150 mm² × 1e-8 = 1.5e-6 a
Real-world example — Hair-width scale measurements
A 70-square millimeter measurement (about the diameter of a human hair) is the kind of value materials engineers regularly express in adjacent micro-scale units like ares for direct comparison across supplier datasheets.
70 mm² × 1e-8 = 7e-7 a
Square Millimeter to Are conversion table
Standard reference values for converting square millimeters to ares:
| Square Millimeter [mm²] | Are [a] |
|---|---|
| 0.01 | 1e-10 |
| 0.1 | 1e-9 |
| 1 | 1e-8 |
| 2 | 2e-8 |
| 3 | 3e-8 |
| 4 | 4e-8 |
| 5 | 5e-8 |
| 10 | 1e-7 |
| 20 | 2e-7 |
| 30 | 3e-7 |
| 40 | 4e-7 |
| 50 | 5e-7 |
| 100 | 1e-6 |
| 500 | 5e-6 |
| 1000 | 1e-5 |
Frequently asked questions
How many ares is 1 square millimeter?
How do I convert square millimeters to ares?
How do I convert ares back to square millimeters?
How many ares is 100 square millimeters?
Popular area unit conversions
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Metric / SI (15 units)
Imperial / US Customary (15 units)
US Survey (5 units)
Indian Subcontinent (16 units)
Other Regional (10 units)
Scientific / Physics (5 units)
Sources & references
Conversion factor (1 mm² = 1e-8 a) 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.