Physical Constants Reference Table
Look up fundamental physical constants including the speed of light, Planck's constant, gravitational constant, and more with units.
Speed of Light in Vacuum
299,792,458 m/s
Symbol: c
Symbol
c
Value
299,792,458
Unit
m/s
All Constants
c: 299,792,458 m/s | G: 6.67430 × 10⁻¹¹ m³/(kg·s²) | h: 6.62607 × 10⁻³⁴ J·s | ℏ: 1.05457 × 10⁻³⁴ J·s | e: 1.60218 × 10⁻¹⁹ C | mₑ: 9.10938 × 10⁻³¹ kg | mₚ: 1.67262 × 10⁻²⁷ kg | k_B: 1.38065 × 10⁻²³ J/K | Nₐ: 6.02214 × 10²³ mol⁻¹ | R: 8.31446 J/(mol·K) | σ: 5.67037 × 10⁻⁸ W/(m²·K⁴) | ε₀: 8.85419 × 10⁻¹² F/m | μ₀: 1.25664 × 10⁻⁶ H/m | α: 7.29735 × 10⁻³ (dimensionless) | g: 9.80665 m/s²