ATS Graticules & Grids · App tutorial APP-003
Browser tool · by All Things Spatial
UTM, State Plane and latitude/longitude on one map — which grid, and how accurate?
Draw the graticule, all 60 UTM zones and every U.S. State Plane zone on one shared 2D/3D map, click any line or zone for its parameters, and see exactly where the three disagree.
Prefer the Esri Calcite Design System build? Same grid engine, Esri’s design language: Calcite build.
The problem
“How far apart are these grids, right here?”
Every coordinate system flattens a curved Earth onto a flat plane, and the flattening always distorts something — distance, area or shape. Most people learn the three systems they use every day as settings in a dialog box: a WKID, a zone number, a “which projection?” dropdown. That works until a survey comes in on State Plane, the imagery is in UTM, the GPS export is in decimal degrees, and something is 200 feet off. Then the question is not “what is the right setting” but “how far apart are these grids here, and by how much can I trust each one”. That is a question you answer by looking at them side by side, and there has never been a convenient place to do that.
Watch it work
The six-minute walkthrough
Six minutes, start to finish: the graticule at 30° down to 1°, clicking a parallel and a meridian near Boulder; UTM zone 13 and its central meridian and boundaries; State Plane Colorado Central with its standard parallels, latitude of origin and false origin drawn on the map; the accuracy table; and the 3D globe where the meridians converge.
What it does
Three systems, one map, every line inspectable
Pick a coordinate system — geographic graticule, UTM, or U.S. State Plane — and the app draws it over an Esri dark basemap in 2D or 3D. The graticule runs from 30° down to 1° intervals, and every parallel and meridian is clickable. UTM draws all 60 zones, 6° wide, each on its own Transverse Mercator central meridian; click a zone and the inspector reports the zone and row letter, the central meridian and both boundaries.
State Plane covers every U.S. zone: pick a state and a zone, and the app frames it and draws the central meridian, the standard parallels, the latitude of origin, the grid-zero line and the false origin on the map, with the WKID, projection and every parameter in the inspector. Switch to 3D and the same lines wrap the globe, so you can see why a UTM zone narrows toward the poles and why the graticule has no scale factor at all. Runs entirely in the browser. Nothing to install, no credits.
Projection Lab
Every flat map distorts — see by how much
The grids above tell you where a coordinate is; the Projection Lab, in the same app, shows what a map projection does to area. Pick a projection, click a country, and the Lab reports two numbers: its true size, measured geodesically on the WGS 84 ellipsoid, and the area the projection actually draws — with the inflation factor between them. On Web Mercator, Greenland’s 2.17 million km² is drawn as 35.40 million km², ×16.3. On Equal Earth the same outline comes out ×1.00.
- 13 projections, each labelled with its EPSG or ESRI code and its property (conformal, equal-area or compromise): Web Mercator, Equal Earth, Winkel Tripel, Robinson, Mollweide, Sinusoidal, Bonne, Gall Stereographic, Eckert VI, UTM zone 15N, North America Albers Equal Area Conic, North America Lambert Conformal Conic and North Pole Azimuthal Equidistant.
- True area vs map area — click a country on the map or pick it from the list for its geodesic area on WGS 84, its drawn area and the inflation factor; Shift-click to measure up to three at once. Africa can be measured as one continent.
- Tissot indicatrix — 500 km circles that show where, and how much, a projection stretches.
- True-size drag — drag a selected country across the map at true size; its outline is rebuilt at every new latitude.
- Side-by-side compare — two projections at once, centre and scale synced.
- Shareable permalinks — the projection, the selection, the comparison and the view are kept in the URL; one click copies it.
- Recording mode — the map and the measurement cards without the control panel, for screen capture and teaching.
Same Lab in Esri’s Calcite Design System: Calcite build.
Limits
What it does not do
It does not convert coordinates. There is no point-to-point transformation, no datum shift (NAD27 → NAD83, NAD83 → WGS84, or between NAD83 realizations), no ground-to-grid combined-factor calculator, and no batch reprojection — it shows you the grids, their parameters and what each projection does to area, and the transformation stays in ArcGIS Pro, PROJ or your survey software where it belongs. The Projection Lab projects its own country outlines on screen to measure them; it does not reproject your data.
The grid viewer covers the three systems most U.S. work runs on: it does not draw MGRS/USNG, national grids outside the United States, or the historical NAD27 State Plane zones. The accuracy figures it quotes — 1:2,500 to 1:1,000 for UTM, 1:10,000 for State Plane — are the design limits of each system, not the accuracy of your data; a poorly controlled survey is poorly controlled in any grid.
The Projection Lab measures Natural Earth 1:50m outlines, which are generalised, so its true areas differ slightly from official national figures. Its UTM, Albers and Lambert options are fixed: UTM zone 15N and the North America Albers and Lambert conic definitions. And the app is a reference, not a record: nothing you click is saved or exported — a Lab permalink only keeps the view in its URL.
Where the data comes from
Where the parameters come from
UTM zone geometry follows the standard definition — 60 zones of 6°, central-meridian scale factor 0.9996, 500,000 m false easting. State Plane zone parameters (projection, central meridian, standard parallels, latitude of origin, false easting and northing) follow the NAD83 State Plane Coordinate System definitions published by NOAA’s National Geodetic Survey and carried in the EPSG registry under the WKIDs the app displays. Projection Lab country outlines are Natural Earth 1:50m (public domain); true areas are geodesic on the WGS 84 ellipsoid, and map areas are planar areas after client-side projection. Basemap and rendering are the ArcGIS Maps SDK for JavaScript and Esri basemaps.
All Things Spatial is not affiliated with or endorsed by NOAA, the National Geodetic Survey, USGS or Esri. Zone parameters are reproduced for reference; confirm them against the NGS definition or your state’s statute before using them for a survey, plat or engineering computation.
Build with us
Need this on your data?
ATS Graticules & Grids is one engine in two builds — a React + Tailwind build in the All Things Spatial brand, and the same ArcGIS Maps SDK for JavaScript grid logic in Esri’s Calcite Design System — and it is a demonstration of what All Things Spatial builds. The real thing — your zones, your data, your brand, your infrastructure — is the work we do for clients.