Here we explain the basics of how to measure for a gate. words in green can be clicked for further explanation. Don't forget we are here to help if you get stuck.
Remember if we are installing the gates for you there is no need to consider any of these points as they will be taken care by us.
In an ideal world posts and wall plates will be perfectly vertical and parallel to each other and while this should be possible with new posts it isn’t always the case with brickwork, old and new . The basic principle remains the same though, taking the measurement at the narrowest point.
The drawings below show:
Posts 
Wall plates 
Gate(s) 
1) How to measure for a single gate
Measure the total opening width. From this deduct the post or wall plate size and the
opening tolerances these will later be covered by gate stops.
This will give you the gate size.
Our example shows brick to brick so we’ll say you’re using wall plates both sides:-
Total opening width from brick to brick is 1315mm deduct 70mm for the hanging wall plate deduct another 70mm for the closing
wall plate , deduct 25mm for the total opening tolerance.
So: 1300mm – 70mm -70mm –
25mm = 1150mm (1.15m) and this is your gate size
2) How to measure for a pair of gates
Measure the total opening width. From this deduct the post or wall plate size and the opening tolerances these will later be covered by gate stops. This will give you the gate size.
Our example here shows brick to brick however as we didn't want to secure onto the neighbours house we have used a wall plate on the left and a post on the right:-
Total opening width from brick to brick is 2670mm deduct 70mm for the left hand hanging wall plate deduct 150mm for the right hand post , deduct 50mm for the total opening tolerance.
So: 2670mm – 70mm - 150mm – 50mm = 2400mm (2.4m) and this is your gate size
3) How to measure for a single 5 or 6 bar gate as standard
Measure the total opening width. From this deduct the post or wall plate sizes then add the overlap. This will give you the gate size.
Our example here shows a post either side with the gate hung on the back of the posts for inward opening.
Total opening width between the hedges / fences is 4000mm (4m) deduct
200mm for the hanging post and 200mm for the closing post plus 50mm for the
total overlaps
So: 4000mm – 200mm - 200mm +50mm = 3650mm (3.65m) and this is your gate
size
4) How to measure for a pair 5 or 6 bar gates as standard
Measure the total opening width. From this deduct the post or wall plate sizes then add the overlap finally deduct the opening tolerance at the centre. This will give you the gate size.
The formula remains the same whether measuring for an equal or unequal pair.
Our example here shows a post either side with the gate hung on the back of the posts for inward opening.
Total opening width between the hedges / fences is 4000mm (4m) deduct 150mm for each of the two hanging posts plus 50mm for the total overlaps, and finally deduct 40mm for the central opening tolerance.
So: 4000mm – 150mm - 150mm +50mm – 40mm = 3710mm (3.71m) and this is your gate size
5) How to measure for a single 5 or 6 bar gate between the posts
Measure the total opening width. From this deduct the post or wall plate sizes
then deduct the space needed for the hinge and latch,
This will give you the gate size.
Bear in mind that the hinge and latch spacing may vary with different manufacturers.
Our example here shows a post either side. Total opening width between the hedges is 4000mm (4m) deduct 120mm for the hinge and 70mm for the mortice latchdeduct 200mm for the hanging post and 200mm for the closing post,
So: 4000mm – 200mm – 200mm – 120mm - 70mm = 3410mm ( 3.41m) and this is your gate size.
If you were to use a Hunting latch / Spring latch the allowance would be greater at 90mm as follows:
4000mm – 200mm – 200mm – 120mm - 90mm (hunting latch) =3390mm ( 3.39m) and this is your gate size.
6) How to measure for a pair of 5 or 6 bar gates between the posts
Measure the total opening width. From this deduct the post or wall plate sizes
then deduct the space needed for the hinges on each gate,
finally deduct the opening tolerance at the centre. This will give you the gate size.
The formula remains the same whether measuring for an
equal or unequal pair.
Our example here shows a post either side.
Total opening width between the hedges / wall is 4000mm (4m) deduct 150mm for each of the two hanging posts, then deduct 120mm for each hinge and finally deduct 40mm for the central opening tolerance.
So: 4000mm – 150mm – 150mm – 120mm – 120mm – 40mm = 3420mm (3.42m) and this is your gate size
7) How to measure for a single gate for above ground automation (Ram Automation)
Measure the total opening width. From this deduct the post or wall plate size and the opening tolerance. This will give you the gate size.
Our example shows posts both sides
200mm posts are needed for above ground Ram automation.
Total opening width from brick to brick / hedge to hedge is 4000mm (4m)
deduct 200mm for the hanging post and 200mm for the closing post, and deduct 40mm for the opening tolerance.
So:
4000mm – 2000mm - 200mm- 40mm = 3560mm (3.56m) and this is your gate size
8) How to measure for a pair of gate for above ground automation (RAM Automation)
Measure the total opening width. From this deduct the post or wall plate size and the opening tolerance. This will give you the gate size.
Our example shows posts both sides 200mm posts are needed for above ground Ram automation.
Total opening width from hedge to hedge is 3000mm (3m) deduct 200mm for the hanging post and 200mm for the closing post and deduct 70mm for the total opening tolerances.
So: 3000mm – 200mm - 200mm- 70mm = 2490mm (2.49m) and this is your gate size
