# Quick start¶

In the XYZ tiling system, the region of the world from 85.0511 (more precisely: `arctan(sinh(π))`) degrees south of the Equator to 85.0511 degrees north is covered at zoom level 0 by a single tile. The number of tiles at each zoom level is `4 ** Z`. At zoom level 1, we have 4 tiles.

```    +-------------+-------------+  85.0511 deg N
|             |             |
|    x: 0     |    x: 1     |
|    y: 0     |    y: 0     |
|    z: 1     |    z: 1     |
|             |             |
+-------------+-------------+   0.0 deg N
|             |             |
|    x: 0     |    x: 1     |
|    y: 1     |    y: 1     |
|    z: 1     |    z: 1     |
|             |             |
+-------------+-------------+  85.0511 deg S

180.0 deg W               180.0 deg E
```

You can get the tile containing a longitude and latitude pair from the `mercantile.tile` function.

```>>> import mercantile
>>> mercantile.tile(-105.0, 40.0, 1)
Tile(x=0, y=0, z=1)
```

You can get the geographic (longitude and latitude) bounds of a tile from the `mercantile.bounds` function.

```>>> mercantile.bounds(mercantile.Tile(x=0, y=0, z=1))
LngLatBbox(west=-180.0, south=0.0, east=0.0, north=85.0511287798066)
```