# Planck Length

Written by Jerry Ratzlaff on . Posted in Relativity

The Planck length is the fundamental unit of length in the system of Planck units.

$$\large{ l_p = 1.62 x 10^{-35}m }$$

## Planck Length Formula

 $$\large{ l_p = \sqrt{ \frac{ h\;G } { c^3 } } }$$

### Where:

 Units English Metric $$\large{ l_p }$$ = Planck length $$\large{ft}$$ $$\large{m}$$ $$\large{ G }$$ = gravitational constant $$\large{\frac{lbf-ft^2}{lbm^2}}$$ $$\large{\frac{N - m^2}{kg^2}}$$ $$\large{ h }$$ = Planck constant (reduced) $$\large{\frac{lbf-ft}{sec}}$$ $$\large{J-s}$$ $$\large{ c }$$ = speed of light in vacuum $$\large{\frac{ft}{sec}}$$ $$\large{\frac{m}{s}}$$