Grid Point Code

Play

Philadelphia

PennsylvaniaUnited States

With a code
#G3GWT-PDN8T
Said aloud
Philadelphia PDN8T

Get the code for your door

What the code says

The Grid Point Code for Philadelphia is #G3GWT-PDN8T. It names a cell 2.56 m north to south and 2.62 m east to west, centred on 39°57'08.59"N, 75°09'49.04"W, and it turns back into that cell on any phone or computer by arithmetic alone: no network, no account, no lookup table.

The point used is the one GeoNames records for Philadelphia, near its centre.

Code
#G3GWT-PDN8T
With a check character
#G3GWT-PDN8T*C
Short form
PDN8T
Cell centre
39.952385, -75.163622
Cell size
2.56 m by 2.62 m
Region
Pennsylvania
Country
United States
Population
1,573,916

How to give this address

On a sign, a form or a delivery note

The whole code, #G3GWT-PDN8T. It needs nothing else: no city, no street, no network to read it back.

Said aloud, in Pennsylvania

Philadelphia PDN8T: a name both people know, then the last five characters. They give back the exact code for anywhere within 4.0 km north or south and 4.1 km east or west of Philadelphia. Further away the same five name somewhere else, which is why the whole code is what goes on a sign.

Copied by hand, or read over a phone

#G3GWT-PDN8T*C. The character on the end catches any single mistyped symbol and any two neighbours swapped.

As a link or a square code

Open it on the map, move to the exact door, and add directions if the code needs help: "blue gate, second floor". The link and the square code carry them. Nothing is kept on this site.

From the city to the door

The first four characters name a cell about 40 km by 41 km here. Each one after that picks one of 25 inside the last, so the whole ten name a spot about the size of a doorway.

  1. G3GWMetropolitan area40 km by 41 km
  2. G3GWTDistrict8 km by 8.19 km
  3. G3GWTPSuburb1.6 km by 1.64 km
  4. G3GWTPDA few streets320 m by 328 m
  5. G3GWTPDNBuilding64 m by 65.5 m
  6. G3GWTPDN8Entrance12.8 m by 13.1 m
  7. G3GWTPDN8TDoorway2.56 m by 2.62 m

More in United States

City, region and population from GeoNames, under CC BY 4.0.