Digital addresses
Grid-Based Addresses Explained
Grid-based addressing divides the map into small cells and gives each one a code. Learn how cell size, naming and lookup work, and what the trade-offs are.
Updated 14 October 2026 · 3 min read
A grid-based address system divides the surface of the Earth into a regular pattern of cells and gives every cell its own code. Anyone standing inside a cell shares that cell's code, and each code refers to exactly one cell.
How a grid is built
Imagine laying a sheet of graph paper over the planet. Each square is a cell. The system then needs two things: a rule that assigns a name to each square, and a way of converting between a name and the square's position. Because the grid is regular, both can be done with simple arithmetic, which keeps the lookup fast and consistent.
Cell size
The size of a cell sets the precision. Large cells give short codes but identify only a neighbourhood. Small cells identify a doorway or a plot but need more characters. Some systems use several levels, with a short code for a large area and extra characters to narrow down.
Strengths
- Predictable. The same position always falls into the same cell.
- Compact. A cell can be named with a short code rather than a long coordinate pair.
- Works anywhere. It does not depend on street names, buildings or language.
- Easy to compute. Software can calculate codes without a database of addresses.
Limitations
- Boundaries. Two points on either side of a cell edge get different codes even if they are very close.
- Cell, not building. A cell does not know about walls. In a dense block of flats, several homes may fall into one cell.
- Needs a tool. People cannot read a location straight from a code; they need a map or lookup.
More detail on constraints is in limitations of digital addresses.
Choosing a point sensibly
When you pick a location for a grid code, choose the point that matters, such as the front door or the gate where a courier should stop, rather than the middle of a large compound. For tips on this, see how to share your location with a courier.
A concrete example
UPCS uses a grid with 3 m x 3 m cells. Each cell has its own code in the form CC-XXXX-XXXX, and the same coordinates always give the same code. For what that size looks like on the ground, read what a 3 m x 3 m UPCS cell means.
Frequently asked questions
What happens at the edge of a grid cell?
Points on opposite sides of a boundary belong to different cells, so two spots a metre apart can have different codes. Choosing the point in the middle of a plot avoids this.