Convert Arcseconds to Turns
Convert Arcseconds (″) to Turns (rev) instantly and accurately.
Conversion Formula
rev = ″ × 7.716049383e-7
About Arcseconds
An arcsecond (″) is 1/3,600 of a degree - π/648,000 rad ≈ 4.848 × 10⁻⁶ rad. It is the fundamental resolution unit of classical astronomy and geodetic surveying. The Hubble Space Telescope delivers ~0.05″ resolution; atmospheric seeing at excellent sites gives 0.4-0.6″. Stellar parallax of Proxima Centauri is 0.7687″, defining its distance of 1.3009 parsecs. The parsec is defined as the distance at which 1 AU subtends exactly 1 arcsecond - giving 1 pc = 3.0857 × 10¹⁶ m. 1″ = π/648,000 rad ≈ 4.848 µrad.
About Turns
A turn (revolution, cycle) equals one complete rotation - 2π rad = 360° = 400 grad. Rotational speed is naturally measured in turns per minute (rpm): a car engine idles at ~750 rpm; a hard disk spins at 7,200 rpm. The factor 2π in physics formulas (ω = 2πf, E = hf = ħω) arises from converting turns to radians. The turn is the natural unit for gear ratios, transformer winding counts, and thread pitch (turns per inch). The tau convention (τ = 2π ≈ 6.2832) proposes 1τ = 1 full turn. 1 rpm = 1/60 Hz = 2π/60 rad/s ≈ 0.10472 rad/s.
Quick Reference Table
| Arcseconds (″) | Turns (rev) |
|---|---|
| 1 ″ | 7.716 × 10-7 rev |
| 2 ″ | 1.543 × 10-6 rev |
| 5 ″ | 3.858 × 10-6 rev |
| 10 ″ | 7.716 × 10-6 rev |
| 25 ″ | 1.929 × 10-5 rev |
| 50 ″ | 3.858 × 10-5 rev |
| 100 ″ | 7.716 × 10-5 rev |