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NAD27 to NAD83 coordinate converter
FAA studies, deeds and older tower records frequently list NAD27 coordinates, while current FCC filings call for NAD83. Convert in either direction with the official NOAA NADCON 5 grids, using decimal degrees or degrees-minutes-seconds format.
34° 42′ 28.98″ N 87° 41′ 34.99″ W
NAD27, converted from NAD83(1986) with NADCON 5.0.
| NAD83(1986) (entered) | 34° 42′ 29.30″ N 87° 41′ 35.10″ W34.708139, -87.693083 |
|---|---|
| NAD27 | 34° 42′ 28.98″ N 87° 41′ 34.99″ W34.708050, -87.693053 |
| Rounded to the second | 34° 42′ 29″ N 87° 41′ 35″ W |
| Shift | 9.9 m south, 2.7 m east10.3 m (34 ft) in all |
| NOAA's stated uncertainty | ±1.00 m latitude, ±0.80 m longitudeOne standard deviation of the NADCON 5 transformation here |
| UTM (NAD27) | UTM Zone 16: 3,840,689.556 m N, 436,531.951 m EUSNG 16SDD3653240690 |
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RF Navigator accepts NAD83 coordinates directly for AM, FM, LPFM, translator and TV studies, while Nexus Broadcast can handle engineering and filing with the FCC.
About this conversion
- All conversions are performed by NOAA, through NCAT, the National Geodetic Survey's service, and its NADCON 5.0 transformation grids. That is the official method for shifting coordinates between NAD27 and NAD83.
- This page's NAD83 is the original realization, NOAA's NAD83 (1986), and FCC applications state coordinates in NAD83. Moving from NAD27 typically shifts a point by tens of meters across the lower 48, and further in Alaska.
- NAD27 covered only the contiguous U.S. and Alaska, so it cannot be used to convert points in Hawaii, Puerto Rico or the territories.
- Both coordinates you enter are assumed to be in the source datum. A positive longitude with no direction is treated as west.
The NOAA tool itself: NCAT (see also NADCON 5 info).
Intended for planning. Not a NOAA or FCC product.