TIP: Click on the map to get details for a tile!

Tiles à la Google Maps

Coordinates, Tile Bounds and Projection

pyramid

How does a zoomable map works?

People are using coordinate systems and map projections to transform the shape of Earth into usable flat maps for centuries.

A map of the entire world is too big to be directly displayed in a computer so there is a clever mechanism for quick browsing and zooming on maps: the map tiles.

The world is divided into small squares, each with fixed geographic area and scale. This clever trick allows you to browse just a small part of the planet without loading the whole map - and you still get an illusion of exploring a single huge document.

Spherical Mercator

Pioneered by Google, now standardized.

Google Maps was one of the first systems displaying dynamic maps on the web. They chose a Spherical Mercator projection because it preserves shape and angles. The entire world looks like a square, which makes it easy to work with on a computer.

Almost every open source and commercial Maps API providers as well as OpenStreetMap and MapTiler Cloud Maps APIs are now using this projection and tiling profile and the tiles are therefore compatible with each other.

mercator

Convert coordinates for using global map tiles

Earth

Degrees
Geodetic coordinates
WGS84 (EPSG:4326)

Longitude and latitude coordinates used by GPS devices for defining position on Earth using World Geodetic System defined in 1984 (WGS84).

HINT: WGS84 geodetic datum specify lon/lat (lambda/phi) coordinates on defined ellipsoid shape with defined origin ([0,0] on a prime meridian).

World

Meters
Projected coordinates
Spherical Mercator (EPSG:3857)

Global projected coordinates in meters for entire planet. Used for raster tile generation in GIS and WM(T)S services.

HINT: Simpler spherical calculation are used instead of ellipsoidal. Mercator map projection deforms size (Greenland vs Africa) and never shows poles.

Pyramid

Pixels
Screen coordinates
XY pixels at zoom

Zoom-specific pixel coordinates for each level of the pyramid. Top level (zoom=0) has usually 256x256 pixels, next level 512x512, etc.

Devices calculate pixel coordinates at defined zoom level and determine visible viewport for area which should be loaded from servers.

mercator

Tiles
Tile coordinates
Tile Map Service (ZXY)

Coordinates of a tile in the pyramid. There is one tile on the top of the pyramid, than 4 tiles, 16 tiles, etc. All tiles have the same size, usually 256x256 pixels.

Only the relevant tiles loaded and displayed for the area of interest / viewport.

MapTiler Platform as a full online mapping solution

MapTiler makes it easy to create and self-host maps for your websites and products. If you are a newbie you couldn't care about complicated cartography things, MapTiler solves it for you. But it isn't mean that it is deprived of advanced functions for experts.

Download the software Try online map cloud
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Resolution and scales

List of resolutions and scales of pyramid in Spherical Mercator projection

Zoom level Resolution (meters / pixel) Map Scale (at 96 dpi) Width and Height of map (pixels)
0 156,543.00 591658710.9 256
1 78,271.52 1 : 295,829,355.45 512
2 39,135.76 1 : 147,914,677.73 1,024
3 19,567.88 1 : 73,957,338.86 2,048
4 9,783.94 1 : 36,978,669.43 4,096
5 4,891.97 1 : 18,489,334.72 8,192
6 2,445.98 1 : 9,244,667.36 16,384
7 1,222.99 1 : 4,622,333.68 32,768
8 611.4962 1 : 2,311,166.84 65,536
9 305.7481 1 : 1,155,583.42 131,072
10 152.8741 1 : 577,791.71 262,144
11 76.437 1 : 288,895.85 524,288
12 38.2185 1 : 144,447.93 1,048,576
13 19.1093 1 : 72,223.96 2,097,152
14 9.5546 1 : 36,111.98 4,194,304
15 4.7773 1 : 18,055.99 8,388,608
16 2.3887 1 : 9,028.00 16,777,216
17 1.1943 1 : 4,514.00 33,554,432
18 0.5972 1 : 2,257.00 67,108,864
19 0.2986 1 : 1,128.50 134,217,728
20 0.1493 1 : 564.25 268,435,456
21 0.0746 1 : 282.12 536,870,912
22 0.0373 1 : 141.06 1,073,741,824
23 0.0187 1 : 70.53 2,147,483,648
epsg-logo

EPSG.io - Coordinate systems worldwide

Open Source project for visualisation of all coordinate system of a world. Convert coordinated online, get coordinates from a map in different projections, browse the coordinate database.

Look at Spherical mercator in EPSG.io
Transform coordinates from WGS84 to EPSG.io

Source code for utilities for conversion between tiles and coordinates

Usage: python globalmaptiles.py [zoom] [lat] [lon]