What it means: regular and full-time reserve personnel who have finished their training and can be deployed: Army 70,950, Royal Navy and Royal Marines 28,261, and Royal Air Force 27,851. The line is the number the MOD said it needed; at 1 April 2021, the last time it was published, the forces were 8,111 short of it. The total is higher if people still in training and the volunteer reserves are counted.

Source: Ministry of Defence, quarterly service personnel statistics, table 3a.