Convert Milliarcseconds to Milliradians
Convert Milliarcseconds (mas) to Milliradians (mrad) instantly and accurately.
Conversion Formula
mrad = mas × 4.848136811e-6
About Milliarcseconds
A milliarcsecond (mas) is one thousandth of an arcsecond - approximately 4.848 × 10⁻⁹ rad. It is the standard unit of precision astrometry. The ESA Hipparcos satellite measured stellar positions to ~1 mas; its successor Gaia achieves 7-100 µas for bright stars. A parallax of 1 mas corresponds to a distance of 1 kiloparsec (3,260 light-years). Very Long Baseline Interferometry (VLBI) resolves well below 1 mas, imaging structures around supermassive black holes. 1 mas = 10⁻³ arcseconds ≈ 4.848 × 10⁻⁹ rad.
About Milliradians
A milliradian (mrad) is one thousandth of a radian (10⁻³ rad ≈ 0.05730°). The MIL-dot reticle system in precision rifle scopes uses milliradians for its elegant property: at range R metres, 1 mrad subtends exactly R mm - so at 300 m, 1 mrad = 300 mm; at 1,000 m, 1 mrad = 1,000 mm = 1 m. Semiconductor laser slow-axis divergence is typically 5-15 mrad. Note: 1 mrad ≠ 1 NATO mil (which is π/3,200 rad ≈ 0.9817 mrad). 1 mrad ≈ 0.05730° ≈ 3.438′ ≈ 206.3″.
Quick Reference Table
| Milliarcseconds (mas) | Milliradians (mrad) |
|---|---|
| 1 mas | 4.848 × 10-6 mrad |
| 2 mas | 9.696 × 10-6 mrad |
| 5 mas | 2.424 × 10-5 mrad |
| 10 mas | 4.848 × 10-5 mrad |
| 25 mas | 0.000121203 mrad |
| 50 mas | 0.000242407 mrad |
| 100 mas | 0.000484814 mrad |