Latitude:
Note: divide min by 60 and enter as decimal.
Ex: for 23o 15" use 23 + (15 / 60) = 23.25
or use this.
Optional for localization correction in USA
West Longitude:
Note: See note for latitude. Don't include minus sign.
Refresh to update table.

The purpose of this web page is to provide a convenient way to calculate angles for a horizontal sundial at a northern hemisphere latitude. There is a great deal of information about sundials on the world wide web and in books. Much of it requires math which many people don't care to do. This could also be helpful if you wish to do a sundial project with children too young for trigonometry. Indeed, that is my purpose.

For information on sundials I recommend:
      The North American Sundial Society FAQ page with practical information.
      Wikipedia - sundials for a comprehensive article.
      Sundials-Theory-Construction a good book by Albert Waugh.
      Latitude from zip code.

Happy dialing!

Last update 14-Jul-2009