BYTETOOLS

Slippy Map Tile Calculator

Work out the XYZ tile for any coordinate and zoom, or the bounding box of a tile, with the Bing quadkey, pixel offset and metres per pixel.

15
Zoom
16,592
Tile X
11,272
Tile Y
32,768
Tiles across

Tile

XYZ path
/15/16592/11272.png
Bing quadkey
120220011012000
TMS Y (flipped)
21,495
Ground resolution
3.1431 m/pixel
Map scale at 96 dpi
1 : 11,879
Tile width on the ground
0.805 km

Tile bounding box

North / south
48.86471476° / 48.85748700°
West / east
2.28515625° / 2.29614258°
Centre
48.8611009, 2.2906494
EPSG:3857 extent (m)
254,382, 6,250,714 → 255,605, 6,251,937

Pixel position inside the 256 × 256 tile

Pixel inside this tile
217, 223
Global pixel at this zoom
4,247,769, 2,885,855
World size in pixels
8,388,608 × 8,388,608

What is the Slippy Map Tile Calculator?

This calculator converts between latitude/longitude/zoom and the XYZ tile numbers that OpenStreetMap, Mapbox, Google and every other slippy map use.

  • Coordinate to tile, tile to bounding box, and quadkey to tile — three directions in one tool
  • Bing quadkey, TMS flipped Y and the standard /z/x/y path all shown together
  • Ground resolution in metres per pixel plus the 96 dpi map scale denominator
  • Tile bounding box in degrees and in EPSG:3857 metres
  • Drawn diagram of the pixel offset inside the 256 × 256 tile
  • No tiles are downloaded and nothing is uploaded — pure local arithmetic

How to use the Slippy Map Tile Calculator

  1. 1

    Choose what you already have: a coordinate, a tile number, or a Bing quadkey.

  2. 2

    Enter the latitude and longitude (or the tile X and Y) and pick a zoom level from 0 to 22.

  3. 3

    Read the tile numbers, the /z/x/y path, the quadkey and the TMS row.

  4. 4

    Check the bounding box, the ground resolution and the pixel diagram showing where your point falls inside the tile.

About the Slippy Map Tile Calculator

This calculator converts between latitude/longitude/zoom and the XYZ tile numbers that OpenStreetMap, Mapbox, Google and every other slippy map use. It applies the standard formulas — x = ⌊(λ + 180)/360 · 2^z⌋ and y = ⌊(1 − ln(tan φ + sec φ)/π)/2 · 2^z⌋ — and reverses them to give the exact bounding box of a tile.

Alongside the tile number you get the Bing quadkey, the flipped TMS row, the pixel offset inside the 256 × 256 tile, the ground resolution in metres per pixel and the map scale at 96 dpi. It is what you want when you are debugging a tile cache, sizing a download, or checking why a marker landed one tile over.

There is no map preview here and no tiles are fetched — the page draws a plain diagram of the tile grid itself. Every calculation runs locally in your browser and nothing is uploaded.

Frequently asked questions

How do you calculate the tile number from latitude and longitude?

Longitude maps linearly: x = (lon + 180) / 360 × 2^zoom. Latitude goes through the Mercator transform first: y = (1 − ln(tan φ + sec φ) / π) / 2 × 2^zoom. Take the floor of both and you have the tile. This tool shows the fractional part too, which is the pixel offset.

What is the difference between XYZ and TMS tiles?

They use the same X and the same zoom but count rows from opposite ends. XYZ, used by Google and OpenStreetMap, counts Y down from the north; TMS counts up from the south. Convert with y_tms = 2^zoom − 1 − y_xyz, which this tool shows for you.

What is a quadkey?

Bing Maps names a tile with a single string instead of three numbers. Each character is a base-4 digit describing which quadrant to take at that zoom level, so the string length equals the zoom. It sorts nicely, which makes it handy as a cache key.

How many tiles are there at each zoom level?

There are 4^zoom tiles: one at zoom 0, four at zoom 1, and about 17.6 billion at zoom 16. That is why bulk-downloading a whole region past zoom 14 gets expensive fast — the tool shows the tiles-across figure so you can multiply it out.

Why is the ground resolution different at different latitudes?

Web Mercator stretches everything by 1/cos(latitude), so a pixel covers less real ground the further you are from the equator. At zoom 15 a pixel is about 4.8 m at the equator but only about 2.4 m at 60° north.

Related tools