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gisopenstreetmapdistance

How to get the size of a tile in map in meters

Hi there I am currently working on geographical-based program and wondering how to get size of a tile.

Let's say that I have Googleplex's coordinate that located in latitude 37.4219999 and longitude -122.0862462. With 15 zoom level, I can get the x is 5271 and y 12706. Here's the picture

enter image description here

So my question is, how to get the size of tile from left to right in meters? And how do I get the specific coordinate bounds of the tile (left-top, right-top, left-bottom, right-bottom)?

Thank you.

Solution

  • The OpenStreetMap wiki page on "Slippy map tilenames" shows the relevant formulas as pseudocode and in various programming languages. For calculating a tile's coordinate bounds, you want "Tile numbers to lon./lat.". To get the bottom and right borders, just add 1 to your tile coordinate in that dimension.

    That page also has a table with the m/px, i.e. meters per pixel values for each of the common zoom levels. Pay attention to the hint about multiplying these values by cos(latitude), as they depend on how far you are from the equator.