The SN0400 Square Kilometre

SN0400 National Grid Square

Based in the Mid and West Wales region of Scotland.

The SN0400 square kilometre intersects with the settlement of Manorbier Newton.

SN0400 is within the post town of Tenby, Pembrokeshire.

The square is within Sir Benfro - Pembrokeshire council.

The Point of Origin (0,0) is 285.69 Kilometres away. This is where the National Grid starts around 80 kilometres west of the Isles of Scilly.

Ordnance Survey Maps for SN0400

If you purchase a map through the links below, we may earn an affiliate commission.

Map Series	link	Ordnance Survey
Explorer 1:25,000 ol36 South Pembrokeshire	Shop for this map on amazon.co.uk	Buy Direct from the Ordnance Survey
Landranger 1:50,000 157 St Davids & Haverfordwest	Shop for this map on amazon.co.uk	Buy Direct from the Ordnance Survey
Landranger 1:50,000 158 Tenby	Shop for this map on amazon.co.uk

This extract is taken from the Ordnance Survey six-inch to the mile series surveyed from 1888-1913. The scale is 1:10,560.

The Square overlayed over the map represents the extent of SN0400 and the vertical and horizontal line divides the square into four quadrants

Dividing the SN0400 Square to get a six figure Grid Reference

A helpful reminder for calculating grid references is across the landing and up the stairs.

For example if your house was located in a square that in the fourth square across and sixth square up and you wanted to work out its six figure grid refence.

First, You would divide the four figure grid reference into three parts. SN , 04 and 00

Count across starting with zero. This would give you three. Make a note that X for Across (A Cross) = 3.

Count up starting with zero. This would give you five. Make a note that Y = 5.

So to put it together SN + 04 + 3 + 00 + 5 would give you the six figure grid reference of SN043005

SN	04		00
SN	04	3	00	5

A six figure grid reference would be accurate to 10 metres. To achieve a greater level of accuracy this 10 metre square would be divided into a grid 10 by 10 and the process repeated.

This would produce an 8 figure grid reference that would be accurate to a square metre!

Corner	Latitude	Longitude	Easting	Northing
South West Corner	51.664516	-4.836079	204000	200000
South East Corner	51.664516	-4.821077	205000	200000
North West Corner	51.673844	-4.836079	204000	201000
North East Corner	51.673844	-4.821077	205000	201000