# Calculate Width and Height of a Google Static Maps Image

Do you know how to calculate the width and height (in degrees minutes) of a Google Static Maps image?

I've found it extremely difficult. The only information you have is:
- The centre of the image (as a Longitude Latitude coordinate)
- The zoom level of the satellite (1 >= zoom <= 25)
- The width and height of the image in pixels

See this image for a visual explanation of the problem:

And from this limited information its very difficult to calculate the image dimensions in degrees minutes, mainly because the zoom level heights (in feet or metres) is not exposed by Google AFAIK. AND because you can't move up on the y axis at a constant value because you have to take into account that the earth is a sphere and not a flat surface so moving up at a constant value won't work (which is what all the answers on StackOverflow provide). It appears meridional points is a solution but the math involved is completely beyond me.

Any advice would be greatly appreciated.

• If the coordinate reference system is Web Mercator, it is a (effectively) a flat surface – BradHards Nov 15 '13 at 1:44