Easily calculate the precise distance and bearing (direction) between two locations. Just paste your GPS coordinates (latitude and longitude) below.
Point A (Start)
Point B (End)
Calculation Results
Geodetic-Grade vs. Spherical Distance
Calculating distance on an oblate spheroid (Earth) requires solving the geodetic inverse problem. While a "Spherical Earth" model (Haversine) is sufficient for simple navigation or logistics, precision engineering and land surveying demand Vincenty's formulae, which accounts for the Earth's flattening at the poles.
Geodetic Accuracy: Spheroidal vs. Spherical Distortions
Using spherical distance models (such as Haversine) over long baselines neglects the Earth's polar flattening (f ≈ 1/298.257). For infrastructure corridors and geodetic control, this introduces systematic errors of up to 0.5% (~5 meters per kilometer), leading to cumulative traverse misclosure and boundary discrepancies:
| Baseline Length | Typical Spherical Error | Recommended Computation Model |
|---|---|---|
| Local (< 10 km) | < 5 meters | Haversine or Projected Grid (SPCS/UTM) |
| Regional (10 – 500 km) | 50 – 2,500 meters | Vincenty Inverse on WGS84 / GRS80 |
| Continental (> 1,000 km) | Up to 5,000+ meters | Geodesic Inverse (Vincenty or Karney geodesic) |
Vincenty's Formula Accuracy
The Vincenty inverse formula used in this tool provides an accuracy of up to 0.5mm (0.0005m) on the WGS84 ellipsoid. It involves an iterative process that converges on the shortest distance (geodesic) between two points.
- Initial Azimuth: The True North bearing measured at the start point (A) towards the end point (B).
- Flattening (f): 1/298.257223563 (WGS84 Standard).
- Convergence: Our engine performs 100 iterations to ensure coordinate stability for global benchmarks.
The Cumulative Boundary & Engineering Rework Exposure: NAD83 vs WGS84
Because the North American Plate moves ~2cm/year, NAD83(2011) and WGS84(G1762) currently diverge by over 2.2 meters. Using a "standard" GPS WGS84 coordinate for a high-precision NAD83 cadastral staking has triggered Boundary Dispute Geodetic Offset claims for foundational rework and utility misplacement.