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Fix your coordinate errors. Continue your journey with our precision tools and guides.
Why Your Coordinates Are "Shifted" on Google Maps
Verdict: It's not your GPS. It's the Map Projection.
The "Web Mercator" Trap
Google Maps, Bing, and OSM use Web Mercator (EPSG:3857). This is a visualization hack, not a geodetic standard.
Official NGA Warning
The National Geospatial-Intelligence Agency (NGA) explicitly warns:
"Web Mercator... is UNACCEPTABLE for official DoD use or mission-critical operations. Deviations can reach 40km at high latitudes."
Why The Shift Happens
If you take high-precision survey coordinates (NAD83, JGD2011) and paste them into Google Maps:
- Tectonic Shift: Web Mercator assumes a static WGS84. Real survey datums move with plates (2-5cm/year).
- Ellipsoid Mismatch: Web Mercator uses a sphere math hack. Survey grids use the ellipsoid.
- Result: 1-3 meter shifts, making boundaries look "off".
Do Not Adjust Your Data to Match the Map!
This breaks the legal validity of your coordinates. Instead, transform the Map to your Data.
← Return to Safety: Valid Coordinate TransformerVerify transformations using PROJ 9.3 standards.
Responsibility Verification Required
Review Professional Boundary CanonReference: USGS Open-File 02-370 / Survey Act (GSI)
Responsibility Verification Required
Review Professional Boundary CanonReference: USGS Open-File 02-370 / Survey Act (GSI)
US State Plane (SPCS) Converters & Local Guides
Professional engineering and surveying transformations from state-specific conformal grids to GPS WGS84.
Certified Geodetic Insight
Verified against professional geodetic standards
The $50,000 Geodetic Drift Liability: 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 $50,000 Professional Liability claims for foundational rework and utility misplacement.
Risk Exposure Metric:
2.2-Meter Tectonic Drift & Epoch Accumulation
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Warning: Verify Your Calculation
Coordinate accuracy varies by device and datum. Do not use these results for legal or construction purposes without checking:
GPS Accuracy Alert
Your phone's GPS can be off by 30 meters. This can cause critical errors in your data.
Check My AccuracyDatum Shift Risk
Using the wrong coordinate system (e.g. WGS84 vs NAD83) creates a permanent 1-meter offset.
Verify My Datum