Convert millimeters to astronomical units
1 mm = 0.00000000000000668458712227 au — exactly. Both units are defined against the SI, so this factor is a fraction, not an approximation.
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Show this value in all 50 length units
- Gigameters Gm 1e-12
- Megameters Mm 1e-9
- Kilometers km 0.000 001
- Hectometers hm 0.000 01
- Decameters dam 0.0001
- Meters m 0.001
- Decimeters dm 0.01
- Centimeters cm 0.1
- Millimeters mm 1
- Micrometers µm 1000
- Nanometers nm 1 000 000
- Picometers pm 1 000 000 000
- Femtometers fm 1 000 000 000 000
- Inches in 0.039 370 078 740 2
- Feet ft 0.003 280 839 895 01
- Yards yd 0.001 093 613 298 34
- Miles mi 0.000 000 621 371 192 237
- Nautical miles nmi 0.000 000 539 956 803 456
- Thous thou 39.370 078 740 2
- Hands hh 0.009 842 519 685 04
- Links li 0.004 970 969 537 9
- Spans span 0.004 374 453 193 35
- Cubits cubit 0.002 187 226 596 68
- Ells ell 0.000 874 890 638 67
- Fathoms ftm 0.000 546 806 649 169
- Rods rd 0.000 198 838 781 516
- Chains ch 0.000 049 709 695 379
- Furlongs fur 0.000 004 970 969 537 9
- Leagues lea 0.000 000 207 123 730 746
- Barleycorns barleycorn 0.118 110 236 22
- US survey feet ft (US) 0.003 280 833 333 33
- US survey miles mi (US) 0.000 000 621 369 949 495
- Ångströms Å 10 000 000
- Microns µ 1000
- Bohr radiuss a₀ 18 897 261.2591
- Planck lengths ℓₚ 6.18714249917e+31
- Astronomical units au 6.68458712227e-15
- Light-years ly 1.05700083402e-19
- Light-seconds ls 3.33564095198e-12
- Light-minutes lmin 5.55940158664e-14
- Parsecs pc 3.24077928944e-20
- Kiloparsecs kpc 3.24077928944e-23
- Megaparsecs Mpc 3.24077928944e-26
- Solar radiuss R☉ 1.43740117867e-12
- Earth radiuss R🜨 1.56961230576e-10
- Point (DTP)s pt 2.834 645 669 29
- Picas pc 0.236 220 472 441
- Scandinavian miles mil 0.000 000 1
- Versts вер 0.000 000 937 382 827 147
- Lis 里 0.000 002
Every row is Millimeter (mm) converted through the meter, in exact rational arithmetic.
How to convert millimeters to astronomical units
Multiply the number of millimeters by 0.00000000000000668458712227 to get astronomical units.
Astronomical unit: Fixed at exactly 149 597 870 700 m by the IAU in 2012.
Millimeter to Astronomical unit conversion table
| Millimeters (mm) | Astronomical units (au) |
|---|---|
| 1 mm | 6.6845871e-15 |
| 2 mm | 1.3369174e-14 |
| 3 mm | 2.0053761e-14 |
| 5 mm | 3.3422936e-14 |
| 10 mm | 6.6845871e-14 |
| 20 mm | 1.3369174e-13 |
| 25 mm | 1.6711468e-13 |
| 50 mm | 3.3422936e-13 |
| 100 mm | 6.6845871e-13 |
| 250 mm | 1.6711468e-12 |
| 500 mm | 3.3422936e-12 |
| 1000 mm | 6.6845871e-12 |
Astronomical unit to Millimeter conversion table
| Astronomical units (au) | Millimeters (mm) |
|---|---|
| 1 au | 149 597 870 000 000 |
| 2 au | 299 195 740 000 000 |
| 3 au | 448 793 610 000 000 |
| 5 au | 747 989 350 000 000 |
| 10 au | 1 495 978 700 000 000 |
| 20 au | 2 991 957 400 000 000 |
| 25 au | 3 739 946 800 000 000 |
| 50 au | 7 479 893 500 000 000 |
| 100 au | 1.4959787e+16 |
| 250 au | 3.7399468e+16 |
| 500 au | 7.4798935e+16 |
| 1000 au | 1.4959787e+17 |
Frequently asked
How many astronomical units are in a millimeter?
One millimeter equals 6.684587122e-15 astronomical units (mm → au). That figure is exact, not rounded.
How do you convert millimeters to astronomical units?
Multiply the number of millimeters by 0.00000000000000668458712227 to get astronomical units.
What is 1 au in millimeters?
One astronomical unit is 149597870700000 millimeters.
What is 10 mm in au?
10 mm = 6.6845871e-14 au.
What exactly is a astronomical unit?
Fixed at exactly 149 597 870 700 m by the IAU in 2012.