๐บ๏ธ UK Grid Tools โ Grid Reference Finder, Postcode Finder & Coordinate Converter
The most accurate way to convert GPS coordinates into British National Grid References, OSGB36, and UK Postcodes โ online and offline.
๐ WHAT IT DOES
UK Grid Tools is a free, professional-grade app that helps you convert your current location (GPS / WGS84 / ETRS89) into:
- ๐ British National Grid Reference
- ๐ OSGB36 (15) coordinates
- ๐ UK Postcode (powered by postcodes.io + offline fallback)
- ๐ Shareable location formats for maps and messaging
Designed for surveyors, engineers, outdoor enthusiasts, GIS professionals, and anyone needing accurate UK location data โ the app ensures your coordinates are within 1 metre of accuracy.
๐ง WHY ITโS ACCURATE
Most apps rely on an outdated 7-parameter Helmert transformation, which can introduce errors of 3โ10m or more across Great Britain.
UK Grid Tools uses the Ordnance Survey OSTN15 transformation model via a 20km grid implementation to achieve:
- โ
<0.15m horizontal accuracy in 95% of the UK
- โ
Fully compliant OSGB36(15) values
- โ
True 10-figure Grid Reference precision
This makes it the most accurate grid reference finder available on Android today.
๐ซ POSTCODE FINDER (HYBRID ONLINE & OFFLINE)
We use the postcodes.io API to instantly retrieve your UK postcode from your GPS location. If you're offline, the app automatically uses a local fallback geocoder (where available) to still show a postcode โ making it great for use in the field.
๐ TOP FEATURES
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Convert GPS to Grid Reference, OSGB36, and Postcode
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Highly accurate coordinate transformation with OSTN15
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View coordinates in multiple formats
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Works both online and offline
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Uses postcodes.io for postcode lookup
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Offline fallback geocoder when no internet is available
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Customise the grid reference output (figures & separators)
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Customise WGS84 display: DMS / DM / DD, signs or quadrants
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Share your location via SMS, messaging apps, or clipboard
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Open current location in maps with one tap
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Tap & hold to copy values
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Built-in GPS accuracy display
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Manual coordinate input (Grid Ref, Easting/Northing, WGS84)
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Card visibility settings โ show only the details you care about
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Light, dark, or system theme
๐ฑ DESIGNED FOR FIELD USE
- Extremely lightweight app (under 10MB)
- No ads, no tracking
- Works indoors, outdoors, or with partial signal
- Great for geocaching, hiking, planning, surveying, field work
๐ VERSION 2.1 โ WHATโS NEW
๐ฎ Postcode card added (auto + fallback)
๐งฉ Card visibility settings to declutter the interface
๐งช Performance improvements & accuracy tweaks
โ
Full Material 3 UI refresh
๐ Still 100% free, with no ads and no login
UK Grid Tools is ideal for anyone needing a reliable grid reference finder, accurate postcode lookup, or high-precision coordinate transformation between WGS84, OSGB36, and British National Grid References. Easily share location within a standard SMS size.
If youโre looking for the most accurate UK Grid Reference app, with built-in postcode lookup and robust coordinate transformation, UK Grid Tools is the one to download.