FAQs

6 & 8 Figure Grid References

A 6 figure grid reference puts you in an area bigger than Wembley Football pitch An 8 figure grid reference puts you in an area less than a quarter of Wimbledon’s centre tennis court

What is the accuracy of a 6 figure grid reference?
A 6 figure grid reference will cover an area of 100m by 100m, i.e. 10,000 square meters, an area bigger than Wembley football pitch.

What is the accuracy of an 8 figure grid reference?
An 8 figure grid reference will cover an area of 10m by 10m i.e. 100 square meters, the equivalent of less that a quarter of Wimbledon’s centre tennis court.

How can I take an 8 figure grid reference on a 1:25000 map using the Shaven Raspberry Romer?
The fine lines that divide each 100m square in half represent an area of 50m. Depending on the location of your position, wither it is nearer the solid line, or the fine  line the 8th figure can accurately be estimated.  Please see the how to use section.

How do I convert an 8 figure grid reference to a 6 figure grid reference?
An 8 figure grid reference consists of 2 groups of 4 numbers, Easting and Northings (8 in total).  All you need to do to convert an 8 figure reference to a 6 figure reference is to remove the last number from each group of 4 numbers.  In other words remove the fourth and eighth digits.  This will move you from an accuracy of 10 square meters to one of 100 square metres.

Is the Grid Tool tough and durable?

Yes.  The tool is varnish coated to prevent scratches to the scales, thus helping eliminate potential errors.

How Can I pay?

Shaven Raspberry accepts payment through PayPal, which in turn accepts major credit cards.  This is a safe and secure way to transact business on the internet.  You can also pay using your credit card if you do not have a PayPal account.

More about 6 & 8 Figure Grid References

Ordnance Survey National Grid

For mapping purposes the UK is divided up into 100km by 100km squares, this is the national grid system.  The zero easting lies off the Western isles, and the 7 Easting lies in the North Sea.  (ie 700km, or 7x 100km grid squares to cover the width of the country).   In the same way the zero northing lies in the Channel, with and the 13 Northing lies North of Shetland.  (ie 1300k, or 13x 100km grid squares to cover the length of the country).

As the grid numbering system repeats its self every 100km, each 100km area is given a unique 2 letter reference.  This is shown in the Ordnance Survey (OS) map key and is also shown in the all of the corners of an OS map.  When giving a grid reference it is imperative that these numbers are quoted in order to ensure the correct 100km area.

6 Figure Grid Reference

A six figure grid reference consists of 2 groups of 3 numbers.  One set to give you your East West fix and one set to give you your North South fix.  Take the west edge of the grid square in which your location lies and read the large 2 figure numbers opposite the end of the line in either the North or South margin first.  These are the Eastings, and tell you how far East/West you are. (A useful analogy to remember is the plane goes along the runway (read eastings first) before it takes off (then read Nothings)!)  This will give you the first 2 figures of your grid reference.  To get the third figure of the first part of the reference divide this 1km square up in to tenths, (every 4mm for a 1:25000 map, and every 2mm for a 1:50000 map) and estimate the number of tenths from the West edge of the square to your location and take note of this number.  This has given you the third figure of the first part of a 6 figure grid reference.

To obtain the second set of numbers repeat the above process, but use the South edge of your grid square in which you location lies and read the  large 2 figure numbers opposite the end of your line in either the East or West Margin (plane taking off!).  These are the Northings, and tell you how far North/South you are.  This will give you the first 2 numbers of the second part of your 6 figure grid reference (numbers 4 & 5).  To get the final figure (6) again repeat the above process, dividing the square in to tenths and estimate the number of tenths from the South edge to your location.  Now you have your 6 figure gird reference.  If this is taken accurately,  this will cover an area of 100m x 100m, or the size of one and a half football pitches.

By using the Shaven Raspberry romer, all estimation is taken out of the equation as the scales are pre divided into tenths and numbered for you to read off.  One of the most common mistakes made is in counting the tenths to obtain the third and sixth figures for the grid reference.  People often count the first tenth as one, where it should always counted as Zero and the second as 1 and so forth.  Again this potential error is eliminated using the Shaven Raspberry romer.

8 Figure Grid References

More and more people are now using hand held GPS units, and are looking to plot the grid references given by their GPS units accurately onto maps, and increasingly Search and Rescue personnel are requiring to provide more precise grid references.   Therefore many people are looking to use 8 figure grid references.  This 8 figure reference represents and area of 10m x10m, in other words the size of an area less that a quarter of Wimbledon’s centre tennis court.

Using the Shaven Raspberry Romer on 1:25000 scale maps it is easy to estimate accurately an 8 figure grid reference because of the fine lines sub dividing the 6 figure tenth scales.  An 8 figure grid reference consists of 2 groups of 4 numbers (Eastings and Northings). In order to obtain an 8 figure grid reference, you need to carry out the exact same procedure to obtain a 6 figure grid reference, dividing your grid square into tenths, but then further sub-divide the 6 figure tenth in which your location lies into further tenths (the 8 figure tenths).

The Shaven Raspberry Romer comes with  fine vertical and horizontal lines dividing each 6 figure grid reference tenth in half.  If your location is to the West of the vertical fine line and south of the horizontal fine line then the fourth figure (Easting), and eighth figure (Northing) of your 8 figure grid reference will be between 0 and 4.  If your location lies the East of the vertical fine line or North of the horizontal fine line then your fourth figure (Easting) and eighth figure (Northing) will be between 5 and 9.
These figures can be easily and accurately estimated depending where your location exactly lies.  The fourth Easting is  then added to the end of the first group of 3 numbers making up your original 6 figure grid reference, and the fourth northing is then added to the end of the second group of 3 numbers making up your original 6 figure grid reference.  This will give you your 8 figure grid reference.