We recommends that your fence posts should be dug into the ground by at least two feet (600mm).

This depth is standard across the fencing industry, with some experts advising deeper for fencing over seven feet (2100mm) in height.

See the table below for recommended post sizes

Fence HeightPost Length
3FT (900MM) Including Gravel Board5FT (1500MM) Post Length
4FT (1200MM) Including Gravel Board6FT (1800MM) Post Length
5FT (1500MM) Including Gravel Board7FT (2100MM) Post Length
6FT (1800MM) Including Gravel Board8FT (2400MM) Post Length
7FT (2100MM) Including Gravel Board9FT (2700MM) Post Length