Open Location Code

The Open Location Code is a geocode based on a system of regular grids for identifying an area anywhere on the Earth.
It was developed at Google's Zürich engineering office, and released late October 2014. Location codes created by the OLC system are referred to as PlusCodes.
Open Location Code is a way of encoding location into a form that is easier to use than showing coordinates in the usual form of latitude and longitude. PlusCodes are designed to be used like street addresses and may be especially useful in places where there is no formal system to identify buildings, such as street names, house numbers, and post codes.
Plus Codes are differently expressed latitude and longitude coordinates, so they can be assigned to any location. They are similar in length to a telephone number but can often be shortened to only four or six digits when combined with a locality. Locations close to each other have similar codes. They can be encoded or decoded offline. The character set avoids similar-looking characters to reduce confusion and errors and avoids vowels to make it unlikely that a code spells existing words. Plus Codes are not case-sensitive and can therefore be easily exchanged over the phone.
Since August 2015, Google Maps has supported Plus Codes in its search engine. The shortened Plus Code is displayed for a location, may be copied, clicked, or transcribed, and can be entered into the address box to display the location on the map. The algorithm is licensed under the Apache License 2.0 and is available on GitHub.

Applications

Plus Codes are increasingly being used for addressing purposes in places that aren't well-served by the traditional street address system. This includes the many unnamed streets in Cape Verde, multiple slums in India, and even some Native American reservations in the United States. In Laxmi Nagar, Pune, the nonprofit Shelter Associates used codes to bring delivery services to specific homes and businesses in the slum for the first time in 2020-21. PlusCodes are also being used by the International Rescue Committee in Somalia for immunization and family planning programs.

Specification

The Open Location Code system is based on latitudes and longitudes in WGS84 coordinates. Each code describes an area bounded by two parallels and two meridians out of a fixed grid, identified by the southwest corner and its size. The largest grid has blocks of 20 by 20 degrees, 18 columns from West to East and 9 rows from the South to the North poles. Those large blocks are then divided into 20 by 20 subblocks up to four times. Near the equator, those subblocks are square both in degrees and in meters. At midlatitudes, while still square in terms of degrees, in terms of meters the blocks are not as wide as they are tall.
After four rounds of 20x20 subdivision, further subdivisions break each block into 20 subblocks, 4 blocks W-E by 5 blocks S-N. That leaves the subblocks wider than they are tall in terms of degrees, but at midlatitudes, this keeps them closer to square in terms of meters. The table shows the various block sizes near the equator, where the widths are maximum. The block widths decrease with distance from the equator.

Code length	2	4	6	8	+	10	11	12	13	14	15
Block size	20°	1°	0.05°	0.0025°		0.000125°	0.1125″	0.0281″	0.0070″	0.0018″	0.0004″
Real size	2,200 km	110 km	5.6 km	280 m		14 m	3.5 m × 2.8 m	0.8 m × 0.5 m	20 cm × 10 cm	5 cm × 2 cm	14 mm × 4 mm

The full grid uses offsets from the South Pole and the antimeridian expressed in base 20 representation. To avoid misreading or spelling objectionable words, the encoding excludes vowels and symbols that may be easily confused with each other. The following table shows the mapping.

Base 10 digit	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19
Base 20 digit	0	1	2	3	4	5	6	7	8	9	A	B	C	D	E	F	G	H	I	J
Code digit	2	3	4	5	6	7	8	9	C	F	G	H	J	M	P	Q	R	V	W	X

The code begins with up to five pairs of digits, each consisting of one digit representing latitude and one representing longitude. The biggest blocks have just two digits. After eight digits, a plus sign "+" is inserted in the code as a delimiter to aid with visual parsing. After a final pair immediately following the "+" delimiter, any subblocks thereafter are coded in a single code digit as follows:
Areas larger than an 8-digit block can be specified by replacing an even number of trailing digits before the + sign with the digit 0, with nothing after the + sign.

Example

Consider, for example, zooming in on the Merlion fountain in Singapore, which has Plus Code. It lies in the block around the equator bounded by −10° South and +10° North, and between 100° and 120° East. It has offsets 80° from the South Pole, and 280° from the anti-meridian; or, 4 and 14 as the first base-20 digits, coded as "6" and "P". Thus, the code is "6P". This may be padded as.
Now, refine this block to a subblock between 1° and 2° N and 103° and 104° E. This adds 11° and 3° to the SW corner. So the base-20 coordinate codes added are "H" and "5". The result is padded to.
After four further refinements, one lands on Merlion Park as.
The next step requires dividing the square so far used, to refine the position into a 4-by-5 grid, and finding the cell to which the coordinates are pointing. This is the cell named "6".

BASE20 Formula

Alternatively, use formula BASE in any Spreadsheet or Calculator to compute the Plus Code. For the coordinates from the previous example:

1.286785N = 91.286785 from South Pole, in Base20 = 4B.5EE in alphanumeric = which is 6H.7PP in OLC digits.
103.854503E = 283.854503 from Anti-Meridian, in Base20 = E3.H1G in alphanumeric = which is P5.V3R in OLC digits.
Combining latitude and longitude alternatively, 6P H5 7V P3 PR.
The last leftover in Base20, /20 latitude and /20 longitude gives 6 in the 4-by-5 grid.

Therefore, the resulting Plus Code is.

Common usage and shortening

It is common to omit the first four characters from the code and add an approximate location, such as a city, state, or country. The above example then becomes. This is supported by the Google Maps app and the plus.codes website, and also by non-Google apps. These short forms of Plus Codes can be used in lieu of a house number in a neighborhood.
Shortened codes cannot be unambiguously encoded or decoded without context. The specification does not rely on any specific database of contextual reference location place names and their exact locations, but there are a variety of geocoding databases which map names to latitude and longitude. Disambiguation requires narrowing the possibilities to within about 40 km of the referenced location. The coordinates of the user's current location can be also used for context, if applicable.

Ex.	Plus Codes	Valid digits	Shortened codes	Precision	Point of interest	Street address	Lat/long of centroid
1		10	, Washington, District of Columbia, USA	6 digits	Washington Monument	2 15th St NW, Washington, DC 20024, United States	38.889437, −77.035313
2		10	, London, United Kingdom	6 digits	10 Downing Street	10 Downing St, London SW1A 2AA, United Kingdom	51.503312, −0.127562
3		11	, Al-Baghdadiyah Al-Gharbiyah, Jeddah, Saudi Arabia	7 digits	Jeddah Flagpole	King Abdullah Bin Abdulaziz Square, Al-Baghdadiyah Al-Gharbiyah, Jeddah 22231, Saudi Arabia	21.507813, 39.169688
4		11	, Schwarzenberg am Böhmerwald, Austria	7 digits	Tri-Border Czechia/Austria/Germany	Tri-Border, 4164 Schwarzenberg am Böhmerwald, Austria	48.771613, 13.839547
5		12	, Shibuya, Tokyo, Japan	8 digits	Hachikō Memorial Statue	2 Chome-1 Dogenzaka, Shibuya, Tokyo 150-0043, Japan	35.659063, 139.700688
6		13	, Ushuaia, Tierra del Fuego Province, Argentina	9 digits			−54.83952050, −68.31214160
7		14	, Arusha, Tanzania	10 digits			−3.36657810, 36.69723315
8		15	, Jakarta, Indonesia	11 digits			−6.21861250, 106.80260626