The root-mean-square (r.m.s) vibration magnitude is expressed in terms of the frequencyweighted acceleration at the seat of a seated person or the feet of a standing person (see Annex B), it is expressed in units of metres per second squared (m/s²).
VDV-yksikkö on metriä sekunnissa teholla 1,75 (m/s1.75), ja toisin kuin tärinän r.m.s-arvo, mitattu VDV on kumulatiivinen arvo eli se kasvaa mittausajan kuluessa.