UD5 Toolkit
GPS Dog Collar Range Estimator – Terrain & Battery
Check the expected tracking range of your GPS dog collar based on terrain (open, hilly, dense) and remaining battery level before an off‑leash hike.
Compass Bearing Calculator - Online Azimuth Between Lat/Lon
Compass Bearing Calculator
Calculate azimuth and distance between two points on Earth using latitude & longitude
Point A (From)
Latitude must be between -90 and 90
Longitude must be between -180 and 180
Point B (To)
Latitude must be between -90 and 90
Longitude must be between -180 and 180
Frequently Asked Questions
A compass bearing (or azimuth) is the horizontal angle measured clockwise from true north to a target direction. It ranges from 0° (North) to 360°, such as 90° for East and 180° for South.
We use spherical trigonometry: bearing = atan2( sin(Δλ) * cos(φ2), cos(φ1)*sin(φ2) − sin(φ1)*cos(φ2)*cos(Δλ) ). This gives the initial forward bearing along a great circle path.
The initial bearing is the direction you start traveling along a great circle. The final bearing differs because the path curves on the sphere. This tool shows the initial compass bearing.
We use the Haversine formula to compute great‑circle distance between two lat/lon points, assuming a spherical Earth with radius 6371 km. Results are displayed in kilometers and miles.
Yes, for basic planning. However, magnetic declination must be accounted for separately if navigating with a magnetic compass. This tool provides true bearings.
Decimal degrees only (e.g., 40.7128 for latitude). Both negative west longitudes and negative south latitudes are supported. Do not use degrees/minutes/seconds.
Minor differences can occur due to Earth model (spherical vs ellipsoidal) or rounding. The Haversine formula provides accuracy within 0.5% for all terrestrial distances.
Qibla Direction Finder – Online Sun Shadow & Compass
Use your device's orientation sensor or manually enter a location to find the bearing toward Mecca. Simple compass tool.
Geolocation to Address - Online Reverse Geocode
Enter latitude and longitude and get a human‑readable address using the browser's built‑in reverse geocoding (if available).
Magnetometer Demo - Online Digital Compass
Use the Magnetometer API to build a digital compass. See magnetic field strength and heading in real time.
Absolute Orientation Sensor Demo - Online 3D Compass
Turn your phone into a 3D compass using the AbsoluteOrientationSensor API. See quaternion and Euler angles in real time.
Geohash Encoder/Decoder - Online Lat/Lon to String
Encode latitude/longitude into a geohash string and decode a geohash back to coordinates with precision info. Local algorithm.
Magnetic Declination Estimator - Online Compass Correction
Get the approximate magnetic declination for a given latitude and longitude. Apply correction to your compass.