The SO4104 Square Kilometre

SO4104 National Grid Square

Based in the South Wales East region of Scotland.

SO4104 is within the post town of Usk, Monmouthshire.

The square is within Sir Fynwy - Monmouthshire council.

The Point of Origin (0,0) is 397.36 Kilometres away. This is where the National Grid starts around 80 kilometres west of the Isles of Scilly.

Ordnance Survey Maps for SO4104

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Map Series	link	Ordnance Survey
Explorer 1:25,000 152 Newport and Pontypool / Casnewydd a Phont-y-pwl	Shop for this map on amazon.co.uk
Explorer 1:25,000 ol14 Wye Valley and Forest of Dean	Shop for this map on amazon.co.uk	Buy Direct from the Ordnance Survey
Landranger 1:50,000 161 Abergavenny & The Black Mountains	Shop for this map on amazon.co.uk	Buy Direct from the Ordnance Survey
Landranger 1:50,000 171 Cardiff & Newport	Shop for this map on amazon.co.uk	Buy Direct from the Ordnance Survey

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 SO4104 and the vertical and horizontal line divides the square into four quadrants

Dividing the SO4104 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. SO , 41 and 04

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 SO + 41 + 3 + 04 + 5 would give you the six figure grid reference of SO413045

SO	41		04
SO	41	3	04	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	51.731596	-2.855883	341000	204000
South East Corner	51.731596	-2.841236	342000	204000
North West Corner	51.740691	-2.855883	341000	205000
North East Corner	51.740691	-2.841236	342000	205000