Standard Charpy V-notch specimens have a width (W) of 10mm and a notch depth of 2mm. The thickness of the specimen (B) can be either 10mm (full-size), 6.7mm (two-thirds size), 5mm (half-size), or even 2.5mm (quarter size).

To convert energy (J) to specific energy (J/cm2), divide the energy absorbed by the area (in cm2) of the untouched ligament.

For example, if the energy absorbed during the testing of a full-size specimen is 100 J, then the specific energy is 125 J/cm2. For a two-thirds specimen, energy absorption of 100 J would be equivalent to 187 J/cm2.