erg/cm²
erg per square centimeter
Surface tensionexact by definition
The erg per square centimetre is the CGS surface energy unit, exactly 10⁻³ N/m, and numerically equal to both the dyne per centimetre and the millinewton per metre. Water at 20 °C is 72.8 erg/cm², the same number as 72.8 mN/m.
Watch out: The numerical identity of dyn/cm, erg/cm² and mN/m is the reason surface tension values have survived unchanged through every unit reform. A table from 1930 in dyn/cm can be read directly as mN/m with no conversion at all.
| 1 erg/cm² | 1 mN/m |