The values of the fundamental physical constants provided at this site are recommended for international use by CODATA and are the latest available.

Physical Constants and Astronomical Data New! Try my Physical Calculator. It is a JavaScript calculator with all of the constants below programmed into it. Physical Constants (converted to CGS units from the NIST Constant Index) Name Symbol Number Exp CGS Units Relative Error (ppm) speed of light in a vacuum c 2.99792458 10 cm s-1 exact Planck constant h 6.6260755(40) -27 erg s 0.60 hbar 1.

Homepage The Department ChemNet Chemistry Information Internet Index User Pages FUNDAMENTAL PHYSICAL CONSTANTS Version of this page using math mode (you need a browser such as Arena!) PostScript Version (without warranty) Exponent (base 10) of decimal numbers: e n = 10n . Units are separated by spaces, positive numbers denote powers, all units to the right of the slash are in the denominator ...