ZiaCon: Free Coordinate Converter

Project number (optional)

Project name (optional)

Point number (optional)

Convert from

Convert to

Locate on the map

Click the map or drag the marker to set your point. The systems that cover it appear below, each with a Use button.

Convert this point to

Click the map or enter a coordinate

Zone grid shades State Plane, UTM, or MTM zones (click a zone to convert to it). Lat/Long adds a graticule. Measure gives azimuth and distance between two points. Which systems apply where is in "What covers what" below.

Vertical (heights)ellipsoid ↔ NAVD88 here · NGVD29 needs the backend

From reference

From height

To reference

To height

Geoid model

Geoid ht N

Units

Ellipsoid ↔ NAVD88: H = h − N, with N from your geoid model (type it, or press Fetch to pull it from the NGS GEOID18 model). The height conversion and grid factors both appear in the report above. NGVD29: any conversion touching NGVD29 needs the VERTCON grid, which runs on the geodesy backend (proj4rb), not in the browser, so it is shown but not yet computed here. Note: GRS80 is the reference ellipsoid, so Ellipsoid means ellipsoidal (GPS) height, not a leveling datum.

From

Paste your points

How it works

Built on the real geodetic math.

US and Canada, coast to coast

All 122 NAD83 State Plane zones for every US state, Canadian UTM and MTM zones, global UTM, and geographic latitude/longitude. Output in US survey feet, international feet, or meters.

The same math the pros use

Conversions run on PROJ definitions straight from the EPSG registry, the same geodetic library behind QGIS and countless survey tools. Not a lookup table.

Find the zone on the map

Click the map or use your location and it suggests the State Plane zone under your feet, then plots the point. Confirm it near a zone line and you are set.

What covers what

Region	Systems in ZiaCon
United States (50 states)	State Plane (all 122 zones) · UTM · lat/long
Puerto Rico & US Virgin Islands	State Plane (EPSG 32161) · UTM 19–20N · lat/long
Canada (east/central)	UTM (NAD83 CSRS) · MTM (Ontario/Quebec/Maritimes) · lat/long
Alberta	3TM (4 ref meridians) · 10TM (Forest/Resource) · UTM · lat/long
British Columbia	BC Albers · UTM · lat/long
Mexico	UTM zones 11–16N · lat/long
Guam	Guam Map Grid · UTM 55N · lat/long
American Samoa	American Samoa Lambert · UTM 2S · lat/long
N. Mariana Islands (CNMI)	UTM zones 54–55N · lat/long
Anywhere else on Earth	UTM · MGRS/USNG · lat/long

Read before you stake anything

NAD83 realizations are selectable, but not yet shifted between. NAD83(2011), NAD83(NSRS2007), NAD83(FBN), NAD83(HARN), and NAD83(1986) share one geometric definition. Only the NADCON5 grids relate them, so ZiaCon applies no shift between them yet (the tool says so when you cross realizations). You can label and project any realization exactly; for cm-level realization-to-realization control, use your published transformation.
NAD83 and WGS 84 are treated as identical. They differ by up to a couple of meters; the identity is standard GIS practice. For tight control, apply your published transform.
NAD27 is approximate by default (mean continental US shift, good to a meter or two). For survey-grade NAD27, switch the NAD27 accuracy option to NADCON grid and load an official NGS NTv2 grid. The grid math is wired; it converts the moment a verified grid loads.
USSD is not supported. The United States Standard Datum (1901) predates NAD27 and is not part of NADCON5, so ZiaCon does not convert it. It is only relevant to pre-1927 records; tell us if you actually need it.
Canadian systems use NAD83(CSRS), treated as NAD83 here. UTM and MTM zones are covered; provincial stereographic systems are not yet in the list.
Pacific territories are covered. Guam (Guam Map Grid) and American Samoa (American Samoa Lambert) are in the system list; the Northern Mariana Islands use UTM zones 54–55N. American Samoa Lambert sits on the older American Samoa 1962 datum (Clarke 1866), so its transform to WGS 84 is approximate. See the coverage table above for what applies where.
Heights are ellipsoid ↔ NAVD88, and need a geoid height N. H (NAVD88) = h (ellipsoid) − N. Enter N yourself or Fetch it from GEOID18; a wrong N gives a wrong orthometric height. NGVD29 conversions need the VERTCON grid (geodesy backend) and are not computed here yet. Verify against a published benchmark before you rely on an elevation.
This is a field and office convenience tool. Check a known control point before you trust a batch. Do not use these numbers as the basis for a boundary, easement, or legal description.
Nothing is uploaded or stored. The conversion happens in your browser. Only the map basemap tiles come from Esri.

Set it up for survey-grade work. The conversions above run on the standard PROJ and EPSG math in your browser. For the cases flagged above, load the official grids from the NGS so the results are production grade:

NAD27 to NAD83. Switch the NAD27 accuracy option to NADCON grid and load an official NGS NADCON5 or NTv2 grid. ZiaCon converts the moment a verified grid loads.
NAD83 realization shifts. The NGS NADCON5 grids relate NAD83(2011), NSRS2007, HARN, FBN, and 1986. Load them to shift between realizations at centimeter level.
NAVD88 heights. The built-in Fetch pulls the geoid height from NGS GEOID18. For offline work, install the GEOID18 model on the geodesy backend.
NGVD29 heights. These need the NGS VERTCON grid, which runs on the ZiaMap geodesy backend (proj4rb), not in the browser.

Setting these up for your firm, or need a system that is not on the list? Talk to us and we will get you production ready.

ZiaCon™ coordinate converter.