Transverse Mercator Calculator
A facility for converting latitude/longitude co-ordinates to co-ordinates in metres on a
Transverse Mercator projection. An Excel Workbook is also available on this page to carry out bulk conversions.
Note:
- The results of using the calculator provided on this page are believed to be accurate to 1
metre, but the accuracy is not in any way guaranteed.
- The results will certainly not, however, be accurate to 1 metre in situations where lat/long co-ordinates are based on a geodetic datum which is different from that used in the selected conversion.
- Do not enter negative values for lat/long co-ordinates west of Greenwich or south of the
equator. Specify W or S instead.
- There are few validity checks on the input data.
- For UTM conversions, the option exists for automatic calculation of the Central Meridian or manual entry of the Central Meridian. The calculation assumes that the standard UTM longitude zones are 6 degrees wide, except for the special zones around Svalbard and south-west Norway. For projections outside of the standard UTM zones you should manually enter the Central Meridian for the projection required.
- This facility requires a Web Browser which recognizes Tables and JavaScript.
TM_LL Excel Workbook:
An Excel Workbook (for Excel 97 or later) is available for converting between Latitude / Longitude co-ordinates and metric Easting / Northing on a Transverse Mercator Projection. This Workbook contains ready-made Functions which perform these calculations. The Workbook is set up with example Worksheets which demonstrate the use of these Functions and which can be easily modified using standard Excel operations to suit your needs. For example, you can enter your lat/long or easting/northing or grid reference data in columns on a worksheet and use the supplied Functions to automatically create columns containing the converted data.
For the UTM Grid and the National Grids of Britain, Ireland, Finland, Italy and Sweden, it will:
- Convert Latitude and Longitude to Easting and Northing in metres.
- Convert Easting and Northing in metres to Latitude and Longitude.
For the UTM Grid and the National Grids of Britain and Ireland, it will:
- Convert Latitude and Longitude to Grid References (MGRS and National).
- Convert Grid References (MGRS and National) to Latitude and Longitude.
The cost of this Workbook is £15 and it can be obtained by paying for it by Debit Card or Credit Card on the PayPal Secure Server by clicking on the following button:
If you have any problem with paying via PayPal, or if you have any questions about the Workbook, Contact Alan Morton. Please note that if you use PayPal, Cookies need to be enabled in your Browser.
When you have paid for this Workbook, it will be sent to you promptly as an email attachment, usually within 24 hours, but please note that there may be delays due to staff holidays during late July and early August.
Equations and Source Code:
If you are interested in the equations involved in converting between geographic co-ordinates (latitude/longitude) and various projections, including Transverse Mercator, the following site is recommended:
Program source code is available for converting geographic co-ordinates (latitude/longitude) to metric co-ordinates and vice versa on a Transverse Mercator projection (Including the UTM, British, Irish, Swedish, Italian and Finnish grids). The source code is currently available in Pascal and Visual Basic, and a reasonable charge is made for supplying the source code. For further information, Contact Alan Morton
For visitors who have come to this page directly rather than from the DMAP home page:
The following additional page on this site may be of interest to you:
Also, you are invited to visit the DMAP home page which describes the DMAP software for Distribution Mapping:
Comments or suggestions about this facility are invited and can be sent to Alan Morton
