Millimeter to Astronomical Unit Converter
Quick answer
To convert Millimeters to Astronomical Units, multiply by 6.684587e-15 (or divide by 1.495979e+14). Therefore, 1 Millimeter (mm) equals 6.684587e-15 Astronomical Units (AU).
Formula: AU = mm × 6.684587e-15. Worked example: 10 mm = 6.684587e-14 AU.
Convert Millimeter (mm) to Astronomical Unit (AU) online with our free unit converter. In length, 1 mm = 6.684587e-15 AU. Explore step-by-step conversion steps, mathematical formulas, and quick conversion reference tables below.
Worked example: converting Millimeter to Astronomical Unit
- Step 1 — start with the formula. AU = mm × 6.684587e-15
- Step 2 — substitute your figure. 10 mm × 6.684587e-15
- Step 3 — read the result. 10 mm = 6.684587e-14 AU
- Step 4 — check it in reverse. mm = AU × 1.495979e+14 returns 10 mm, which matches the figure you started with.
Length Converter
31 units available
1 mm = 6.684587e-15 AU
Formula:
AU = mm × 6.684587e-15With your value: 1 mm = 6.684587e-15 AU
How big is that?
Everyday references on a logarithmic scale, all expressed in millimeter so you can sanity-check the result.
Other Millimeter to Astronomical Unit conversions
Millimeter to Astronomical Unit Conversion Table
| Millimeter (mm) | Astronomical Unit (AU) |
|---|---|
| 0.5 | 3.342294e-15 |
| 1 | 6.684587e-15 |
| 2 | 1.336917e-14 |
| 5 | 3.342294e-14 |
| 10 | 6.684587e-14 |
| 15 | 1.002688e-13 |
| 20 | 1.336917e-13 |
| 25 | 1.671147e-13 |
| 50 | 3.342294e-13 |
| 100 | 6.684587e-13 |
| 250 | 1.671147e-12 |
| 500 | 3.342294e-12 |
| 1000 | 6.684587e-12 |
Astronomical Unit to Millimeter Conversion Table
| Astronomical Unit (AU) | Millimeter (mm) |
|---|---|
| 0.5 | 7.479894e+13 |
| 1 | 1.495979e+14 |
| 2 | 2.991957e+14 |
| 5 | 7.479894e+14 |
| 10 | 1.495979e+15 |
| 15 | 2.243968e+15 |
| 20 | 2.991957e+15 |
| 25 | 3.739947e+15 |
| 50 | 7.479894e+15 |
| 100 | 1.495979e+16 |
| 250 | 3.739947e+16 |
| 500 | 7.479894e+16 |
| 1000 | 1.495979e+17 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Millimeter (mm)
Length
Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).
Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)
Bureau International des Poids et Mesures · Reviewed 2026-07-01
Astronomical Unit (AU)
Length
The astronomical unit is exactly 149 597 870 700 m (IAU Resolution B2, 2012).
Source: IAU Resolution B2 (2012) — definition of the astronomical unit; IAU B2 (2015) nominal values
International Astronomical Union · Reviewed 2026-07-01
How to Convert Millimeter to Astronomical Unit
To convert from Millimeter (mm) to Astronomical Unit (AU), multiply the value by 6.684587e-15.
Formula: AU = mm × 6.684587e-15
Reverse: mm = AU × 1.495979e+14
Step-by-Step Example
- Start with your value in Millimeter. For example: 5 mm
- Multiply by the conversion factor: 5 x 6.684587e-15
- The result is: 3.342294e-14 AU
Millimeter and Astronomical Unit Relationship
This conversion bridges the Metric (SI) and Astronomical measurement systems, commonly required when translating scientific data, international engineering specifications, or trade standards. Since 1 Millimeter represents a fraction of a Astronomical Unit (1 Astronomical Unit ≈ 1.496e+14 Millimeters), the Astronomical Unit is the larger measurement interval. Understanding the relationship between Millimeter and Astronomical Unit is essential for accurate calculations in physics, engineering, commerce, and daily applications.
About Millimeter
The millimeter equals one thousandth of a meter and is used for precise measurements in engineering and manufacturing.
Common uses of Millimeter: engineering, rainfall measurement, manufacturing.
About Astronomical Unit
The astronomical unit (AU) is defined as exactly 149,597,870,700 metres, close to the mean Earth–Sun distance. It is the natural yardstick for the Solar System.
Common uses of Astronomical Unit: planetary science, orbital mechanics, astronomy.
Frequently Asked Questions
- How many Astronomical Units are in 1 Millimeter?
- There are exactly 6.684587e-15 Astronomical Units in 1 Millimeter. This means the conversion factor from Millimeter to Astronomical Unit is 6.684587e-15.
- What is the formula to convert Millimeter to Astronomical Unit?
- The formula to convert Millimeter to Astronomical Unit is: AU = mm × 6.684587e-15. For example, to convert 10 Millimeters to Astronomical Units, you would multiply 10 by 6.684587e-15.
- What is a Millimeter?
- The millimeter equals one thousandth of a meter and is used for precise measurements in engineering and manufacturing.
- What is a Astronomical Unit?
- The astronomical unit (AU) is defined as exactly 149,597,870,700 metres, close to the mean Earth–Sun distance. It is the natural yardstick for the Solar System.
- What are the common uses of Millimeter?
- The Millimeter is commonly used in engineering, rainfall measurement, manufacturing.
Related Length Conversions
Cite this page
UnitConvertLab. (2026). Millimeter to Astronomical Unit converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/millimeter-to-astronomical_unit