Officials at the Ordnance Survey regard an area of farmland in Lancashire’s Forest of Bowland as the exact centre of England, Scotland and Wales.
But if Scotland were to leave the Union, the UK mainland’s central point would switch to Walmley, near Sutton Coldfield.
Ordnance Survey experts use the “gravitational” method to settle on geographical centres, which calculates the point at which an area of land would balance horizontally on the head of a theoretical pin.
The method - said by experts to have been used by ‘everyone from Captain Cook to NASA’ - puts the current centre of Great Britain as a spot 7 km north-west of Dunsop Bridge in Lancashire.
If Scotland bids farewell to the union, the new centre point - taking into account the Isle of Man - would be near the Oak and Ash pub on Calder Drive, Walmley.
Disregarding the Isle of Man, the new “gravitational” centre would be a field to the east of Walmley near the A38.
Officials at the Ordnance Survey are keen to point out that there are several other methods of establishing the centre point of the British mainland and the UK as a whole.
Rob Andrews, the mapping agency’s head of media, said: “This is one of the most common questions which we are asked.
“The truth is that there are several ways to calculate the centre and therefore several different answers.
“At Ordnance Survey, we use the gravitational method. The location of Great Britain’s true centre may never be entirely clear but the calculations we have made are as close as we feel we can get.”
• The Scotsman will be running a live blog to cover the referendum on Scottish independence, with news, pictures, tweets and much more from around Scotland and further afield as the country goes to the polls.