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NAD27 to NAD83 coordinate converter
Old tower records, deeds and FAA studies often give coordinates in NAD27; today's FCC filings use NAD83. Convert either way with NOAA's official NADCON 5 grids, in decimal degrees or degrees, minutes and seconds.
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About the conversion
- Every conversion is NOAA's: the National Geodetic Survey's NCAT service with the NADCON 5.0 transformation grids, the official way to move coordinates between NAD27 and NAD83.
- NAD83 here is NOAA's NAD83 (1986), the original NAD83; FCC applications give coordinates in NAD83. The shift from NAD27 is typically tens of meters in the lower 48 and more in Alaska.
- NAD27 was used in the contiguous U.S. and Alaska only, so points in Hawaii, Puerto Rico and the territories can't be converted from it.
- The two coordinates entered are taken as being in the datum you convert from. A bare positive longitude is read as west.
NOAA's own tool: NCAT (and about NADCON 5).
For planning. Not a product of NOAA or the FCC.