H3 Hex Index Helper
Use coordinates as the basis for hexagonal spatial index workflows popular in modern geospatial apps.
By Aryan Khan, Founder & Editor · Updated October 2026
For example, H3 resolution 9 cells average about 0.105 km² — city-block scale — while resolution 7's 5.16 km² cells swallow neighbourhoods whole; choosing the resolution is choosing the analysis.
How to use H3 Hex Index Helper
Use the workspace to prepare coordinates, then use an H3 library or compatible GIS tool to calculate indexes.
H3 is a hierarchical spatial index. This workspace does not calculate or decode H3 indexes or cells; it converts supported global coordinate formats.
- 1Enter a point.
- 2Carry coordinates into your H3-enabled toolchain.
What people use H3 Hex Index Helper for
1. Ride, delivery and demand analytics
H3's home turf: bin trips and demand into equal-friendliness cells. Compare with the square-string approach of the Geohash Encoder before choosing.
2. Choosing a resolution
The table on this page maps resolutions 0–15 to average cell areas — the choice that decides whether your analysis sees blocks or boroughs.
3. Neighbourhood operations
Rings around a cell (k-ring) are uniform in hexagons — surge zones and catchments drawn in cell steps behave the same in every direction.
4. Privacy-aware aggregation
Aggregating counts by cell can reduce detail, but it does not guarantee privacy. Use appropriate disclosure controls and assess re-identification risk.
Worked examples
A square cell has two neighbour distances (edge and corner); a hexagon has one. Movement, spread and diffusion models stop lying about diagonals the day they switch to hexagons.
A hexagon grid cannot tile a sphere perfectly — H3 inherits exactly 12 pentagon cells from its icosahedron base, one famously in the Atlantic. Every H3 user meets them eventually; the helper's framing prepares you.
H3 resolutions, average cell areas
From Uber's published H3 table (averages — cells vary slightly across the globe).
| Resolution | Avg cell area | Feels like |
|---|---|---|
| 0 | ~4,357 km² | A small country |
| 5 | ~253 km² | A metro area |
| 7 | ~5.16 km² | A district |
| 9 | ~0.105 km² | A city block |
| 11 | ~0.00215 km² | A building plot |
| 15 | ~0.0000009 km² | A desk — the joke resolution |
Edge lengths scale with area: res 9's average edge is ~174 m, res 7's ~1.22 km. Cells are indexed by a 64-bit integer usually written in hexadecimal — hence 'hex' twice over.
How to interpret the result
The most common errors come from using a correct result to answer the wrong geographic question. Keep these points in mind for H3 Hex Index Helper:
- Match precision to source: consumer GPS earns about five decimals; quoting six or seven implies a survey you didn't do. Rounding deliberately is honesty, not loss.
- Adopt one storage format — decimal degrees, WGS84, five or six decimals — for every dataset you own, and convert at the edges for display. Mixed notations in one column are the root of nearly every coordinate bug.
Limits & appropriate use
Coordinates are lossless in principle and lossy in practice, and every loss is human: swapped axes, wrong hemispheres, datum relics, precision theatre. The converters eliminate the notation problem completely — DMS, UTM, MGRS and Plus Codes are exact translations on WGS84 — but they cannot eliminate the provenance problem: a number without its datum and its source is a rumour. Old NAD27-era documents, hand-typed sheets and seven-decimal CSVs each carry their own failure signature, and the honest tool answers with validation errors and visible pins rather than silent corrections.
The practical boundary is therefore organisational, not mathematical: teams that standardise storage (decimal, WGS84, sane precision) and ritualise the map check enjoy a lossless system; teams that don't accumulate expensive folklore. For work beyond consumer frames — control points, machine guidance, legal description — the escalation is geodetic: licensed surveyors, published transformations and national datums. Everything between a pasted waypoint and that door is exactly where this toolset lives.
- Datum-critical legacy data → published grid transformations (NTv2/HTDP).
- Control points and machine guidance → licensed geodetic survey.
- Aviation/marine charts → the chart's own datum and notation, verbatim.
Data & methodology
The shared converter handles common coordinate formats but does not calculate or decode H3 indexes.
For source details, licences and model limitations, see Data Sources and Methodology.
Key terms worth knowing
- DMS
- Degrees-minutes-seconds notation; 1° = 60′ = 3600″.
- UTM
- Metre-based zone/easting/northing grid on the WGS84 ellipsoid.
Editorial guidance: MapBench explains the method and limitations so the tool can be used as a transparent reference, not as a black-box answer. For legal boundaries, safety-critical routing, surveying, engineering, regulated decisions or official statistics, verify the result with the responsible authority or a qualified professional.
Category: Coordinates. Results are intended for everyday analysis and planning unless a page explicitly states otherwise.
Method, assumptions & limits
- This tool’s method
- The shared converter handles common coordinate formats but does not calculate or decode H3 indexes.
- Before relying on the answer
- Record the coordinate order, signs, format and datum where specified. In GeoJSON, positions are longitude first; many input forms ask for latitude first.
- What the result cannot establish
- A format conversion preserves the source measurement's uncertainty. Extra digits do not improve the original GPS fix.
Coverage: Worldwide. Search, basemap and external data requests may use third-party services; browser-based does not mean every operation is offline. Read the source and licence notes, calculation methodology and privacy policy. If a result looks inconsistent, report a correction with the inputs and mode used.
Frequently asked questions
Clear answers about the calculation, accuracy and appropriate use.
Uber H3 library?
This page frames the workflow; production apps embed the H3 library directly.
Which datum do these coordinate tools use?
MapBench location tools generally use WGS84 latitude and longitude, the same global reference system commonly used by GPS and web maps.
Do more decimal places always mean better accuracy?
No. More digits increase numeric precision, but they cannot improve the accuracy of the original GPS, survey or source data.
Can I copy the result into GIS software?
Usually yes. Check the format, axis order and datum expected by the destination software before importing.
Is this the Uber H3 library?
No. This workspace does not calculate or decode H3 indexes. Use the official H3 library or compatible GIS software.
H3 versus geohash?
Hexagons versus rectangles: uniform neighbours versus prefix simplicity. Geohash wins on string tricks, H3 wins on spatial statistics — many stacks use both.
H3 versus S2?
Google's S2 (squares on a cube-sphere) is the other modern system. The choice is ecosystem: H3's analytics community versus S2's geometry rigour.
Are cells exactly equal-area?
No. H3 cell areas vary by location and resolution; published values are averages.
What is a k-ring?
Cells within k grid steps of a centre cell. Pentagon distortions can affect neighbourhoods, so use the H3 library rather than assuming a fixed count everywhere.
Pentagons break things?
Pentagon cells have 5 neighbours instead of 6; libraries handle them, algorithms should be told. Twelve exist, always — sphere geometry's tax.
Point to cell is many-to-one?
Deliberately — indexing trades the point for its cell, the foundation of aggregation and privacy uses.
Hierarchies?
Each cell has a parent at the next coarser resolution (roughly 7 children per parent) — the tree that rollups are built on.
Related tools and resources
Rectangles: the Geohash Encoder; area grids: the GARS Converter; military points: the MGRS Converter.
More free tools
Sources, methodology & editorial trust
- ✓ Browser-first processing where supported
- ✓ External sources are documented
- ✓ No account required for public tools
- ✓ Review data sources
Calculations are documented with their assumptions, limitations and source context rather than presented as unexplained answers.
Reviewed and maintained by Aryan Khan, Founder & Editor of MapBench.
Part of our coordinates hub
H3 Hex Index Helper sits in the coordinates cluster, alongside 63 other tools that answer neighbouring questions with different methods or datasets.
You may also need
When this answer is only part of the job, these clusters cover the next step.
Read the guide behind this tool
Understanding GPS Coordinates: Formats, Datums and Precision — A practical guide to latitude/longitude: what decimal degrees and DMS really mean, why datums matter, and how many decimal places you actually need.