Geo Tools
Distances, coordinates, OS grid references, UK postcodes, bearings and time zones, worked out in your browser and mostly offline. Learn more
Address/Place Locator
Coordinates for towns, airports, postcodes and any address.
Area Unit Converter
Acres, hectares, sq ft, m² and more at once, or from length × width.
Bounding Box Calculator
The box round a radius or points, in the order your API needs.
Compass Bearing Calculator
Bearings there and back, rhumb lines and where a bearing takes you.
Coordinate Converter
Any format to decimal, DMS, OS grid, UTM, MGRS and plus codes.
Country Code Reference
ISO codes, domains, dialling codes and currencies for 249 countries.
Distance Between Two UK Postcodes
Postcode to postcode distances and delivery radius checks, offline.
Distance Calculator
As-the-crow-flies distance between places, with stops.
Distance Unit Converter
Miles, km, feet and inches, nautical miles and more at once.
GPX/KML Route File Viewer
See a GPX, KML or GeoJSON route with climb, speed and a profile.
Great-Circle Flight Distance Calculator
Airport to airport distance, heading and rough flight time.
IP Geolocation Lookup
Roughly where an IP address is, and which ones can’t be located.
Lat/Long List Formatter
Reformat a list of coordinates or export CSV, GeoJSON or GPX.
Map Preview
Show a place on OpenStreetMap and get the code to embed it.
Midpoint Calculator
Halfway between two places, or the centre of a group, to meet.
My Current Location
Your coordinates, grid reference and nearest town, ready to share.
Nearest Town & City Finder
The ten nearest towns and cities, with distance and direction.
OS Grid Reference Converter
GPS to OS grid references and back, with the proper datum shift.
Polygon Area Calculator
Area and perimeter of a field or plot from its corners or GeoJSON.
Random Coordinate Generator
Evenly spread random points in a box or round a place.
Speed, Distance & Time Calculator
Solve for speed, distance or time, with running pace.
Time Zone by Coordinates
The time zone, local time and next clock change anywhere.
UK Postcode Checker & Reference
Check a postcode’s format, area, sector and town.
UTM Coordinate Converter
Latitude/longitude to UTM and MGRS, including Norway’s zones.
Free maps, coordinates and distance tools that work offline
Most of these tools run entirely in your browser, using reference data built into the page, so they answer instantly and keep working without a signal. Measure the straight-line distance between towns, coordinates or postcodes with the Distance Calculator, find somewhere fair to meet with the Midpoint Calculator, or check which customers fall inside a delivery radius with Distance Between UK Postcodes. The Great-Circle Flight Calculator takes airport codes and gives a rough flight time, and the Compass Bearing Calculator gives the heading there and back.
Walkers, climbers and surveyors can turn a phone’s GPS position into an Ordnance Survey grid reference with the OS Grid Reference Converter, which applies the proper datum shift, or paste coordinates in any format into the Coordinate Converter to get decimal degrees, DMS, UTM, MGRS and plus codes. My Current Location gives a shareable fix with your nearest town, the GPX/KML Route File Viewer draws a walk, run or ride with its climb and speeds, and the Polygon Area Calculator measures a field or plot in acres and hectares.
For everyday reference, there’s the UK Postcode Checker, the time zone and local time anywhere, ISO country codes with dialling codes, and converters for area, distance and speed and pace. Only a few tools, such as IP lookup and address search, use an outside service, and only when you press their button.
Questions and answers
- Why is the distance different from the one my sat nav gives?
- These tools measure the straight-line (“as the crow flies”) distance over the Earth’s surface, the shortest possible path. Roads and railways have to follow the ground, so journeys are typically 20 to 40 per cent longer. For the straight-line figure, the tools use the WGS84 ellipsoid that GPS uses, which is more accurate than the simple sphere many calculators assume.
- Why doesn’t my phone’s position match the OS grid reference on my map?
- Phones use the worldwide WGS84 datum, while Ordnance Survey maps use OSGB36, and the two differ by up to about 120 metres in Great Britain. A converter that skips the datum shift puts you a field away. The OS Grid Reference Converter applies the standard Helmert transformation, accurate to about 5 metres, which is fine for navigation.
- What’s the difference between the Coordinate Converter and the Lat/Long List Formatter?
- The Coordinate Converter takes one location in any format, from degrees-minutes-seconds to an OS grid reference, UTM or a plus code, and shows it in all of them. The Lat/Long List Formatter is for many points at once: paste a list or a spreadsheet column and convert every line to one format, or export the lot as CSV, GeoJSON, WKT or GPX waypoints.
- Do these tools send my location anywhere?
- No, unless you ask. Positions from “use my location” stay in your browser, and the towns, airports, postcodes and time zones are looked up from data built into the page. A few tools have an optional button that contacts an outside service, such as IP Geolocation, Place Locator’s OpenStreetMap search, the exact-postcode lookups and “Show on a map”. Nothing is sent until you press it, and the Privacy page lists each one.
- How accurate are the UK postcode distances?
- Without going online, each postcode is placed at the centre of its postcode sector (such as SW1A 1) using the ONS Postcode Directory, which in towns is usually within a few hundred metres of the actual postcode, and further out in rural areas. That’s plenty for delivery radiuses and travel estimates. For pinpoint accuracy, press the button to look up the exact postcodes online.