The diameter of the base of a haycock sited on a field will be approximately 2 metres wide, and can be judged by sight or by the length of a pitchfork. In general those planned for move horse and cock-shifter may be larger than those planned for move by small tractor, e.g. Ferguson 20, with rear prong attachments where balance issues may result.
The actual site of the haycock must be chosen with a little care. It should not be in a dip where water and dampness may gather as the haycock seasons in the field.