Bounding Box Calculator
Choose a centre coordinate and radius to generate a quick latitude/longitude bounding box for APIs, map queries and spatial filtering.
By Aryan Khan, Founder & Editor · Updated October 2026
For example, a 10-kilometre box around Times Square runs from 40.6679 to 40.8481 latitude and −74.1039 to −73.8671 longitude — computed, ready to paste into an API call.
How to use Bounding Box Calculator
Databases think in rectangles. Give yours the right one:
The Bounding Box Calculator takes a centre coordinate and radius and returns the latitude/longitude bounding box around it — the min/max extent APIs, map queries and spatial filters ask for. Enter centre and radius and copy the four numbers that turn a circle into a rectangle a database can search.
- 1Search or select the centre point.
- 2Enter a radius in kilometres.
- 3Copy the north, south, east and west bounds.
What people use Bounding Box Calculator for
1. API spatial queries
Overpass, geocoding and places APIs filter by bbox. Compute the extent here instead of guessing degree offsets — the Coordinate Bounding Box Generator is the sibling variant.
2. Database pre-filtering
The classic two-step: cheap bbox filter first, exact distance second. The box this page builds is step one done correctly at any latitude.
3. Map viewport extents
Tile and feature requests need extents in degrees — the centre-plus-radius form is how humans think, the box is how servers answer.
4. Data exports by area
Clip a dataset to 'around here' before the heavy geometry starts. The box is the coarse knife that saves the fine one.
Worked examples
Centre 40.7580, −73.9855, radius 10 km → box lat 40.6679…40.8481, lon −74.1039…−73.8671. Note the longitude span (0.2368°) is wider than the latitude span (0.1802°) — at 41°N, degrees of longitude are shorter, so more of them fit in 10 km.
The box's corners lie outside the radius (up to ~41% farther at the diagonals). Filters must refine box results with true distance — the FAQ's warning is the professional habit.
Anatomy of the output
The four numbers and what each guards.
| Value | Meaning | Watch out |
|---|---|---|
| min_lat / max_lat | Southern and northern edges | Radius ÷ ~111 km per degree, ellipsoid-refined |
| min_lon / max_lon | Western and eastern edges | Span widens toward the poles |
| Format order | APIs differ: (S,W,N,E) or (W,S,E,N) | Read the API's docs — swapped order is the classic bbox bug |
| Date line | Boxes crossing ±180° split in two | Handle as two queries |
Near the poles a radius can reach around the world in longitude — the calculator's handling there is stated in its method note rather than papered over.
A bounding box is a rectangular extent for search and APIs, not the true shape of the area
Bounding boxes reduce a study area to minimum and maximum latitude and longitude. They are useful for API queries, viewport fitting, tile requests, spatial filtering and documenting the extent of a dataset. The rectangle will usually include land or features outside the actual area of interest because it describes an envelope, not a polygon boundary.
Be careful around the antimeridian and near the poles, where naive minimum/maximum longitude logic can produce an unexpectedly huge box. For precise inclusion tests, use the real polygon after using the bounding box as a fast first filter.
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 Bounding Box Calculator:
- 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
Latitude span uses approximately 111.32 km per degree; longitude span is adjusted by cosine(latitude).
For source details, licences and model limitations, see Data Sources and Methodology.
Key terms worth knowing
- Datum
- The reference shape model (WGS84 for GPS) that coordinates are angles against.
- DMS
- Degrees-minutes-seconds notation; 1° = 60′ = 3600″.
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
- Latitude span uses approximately 111.32 km per degree; longitude span is adjusted by cosine(latitude).
- 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.
Is the box the same as a radius circle?
No. It is a rectangular envelope around the centre. Corners extend farther than the requested radius.
Is longitude handling exact near the poles?
The quick formula becomes unstable very near the poles; use a geodesic GIS library for polar production work.
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.
Why is the longitude span wider than latitude's?
Longitude degrees shrink toward the poles (84.4 km at New York's latitude against 111.0 for latitude). The box compensates — eyeballing equal degree offsets is the amateur error this page prevents.
Kilometres or miles?
Both units are accepted for the radius, per this site's convention.
Date-line centres?
A centre near ±180° produces a box that wraps; split it into two queries for APIs that cannot wrap.
How big a radius is sane?
Boxes are for local extents. Continental radii belong to polygon filters, not envelopes — the corners' distortion grows with size.
Antimeridian and poles aside — marine use?
Fisheries and shipping queries use bboxes heavily; the same envelope logic applies, with the corner warning doubled at sea.
Can I build the box from two corners instead?
That is the Coordinate Bounding Box Generator's shape — corners in, normalised extent out.
Related tools and resources
Corners version: the Coordinate Bounding Box Generator; points on the circle: the Coordinate Radius Points Generator; centre math: the Coordinate Offset Calculator.
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
Bounding Box Calculator 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.