Corrections
When we find an error, or a reader reports one, we fix it and list it here, newest first. To report an error, email hello@simplemaplab.com with “Correction:” in the subject.
| Date | Page | What was wrong | What it says now |
|---|---|---|---|
| Oct 6, 2026 | Study CSV downloads | Each study CSV began with a “#” credit line, which spreadsheets and pandas read as the header — shifting every data column. | The CSV starts with the real header row; the credit moved into a quoted “source” column, so every column parses correctly. |
| Oct 6, 2026 | How Many Counties in Each US State | Independent cities were folded into county counts — e.g. Virginia shown as “133 counties”, Maryland “24”. | Counties and independent cities are counted separately: Virginia 95 counties + 38 cities; Maryland 23 counties + 1 city. |
| Oct 5, 2026 | County pages for 14 two-time-zone states | The time-zone fact showed a single zone (e.g. Texas “Central”), or a raw IANA string like “America/Boise”. | Shows both zones the state spans, e.g. Texas “Central (CT), Mountain (MT)”; Idaho “Mountain (MT), Pacific (PT)”. |
| Oct 5, 2026 | Horizon Distance Calculator | Atmospheric refraction multiplied the geometric horizon distance by 1.0746 (about +7.5%). | Multiplies by 1/√(1−k) ≈ 1.0721 (about +7.2%). |
| Oct 5, 2026 | Map Drawer | The JFK → LHR example arrow reported 5,571 km / 3,462 mi great-circle. | 5,540 km / 3,443 mi, computed from the endpoints. |
| Oct 2, 2026 | Geographic Lines pages (Equator, Tropics, Polar Circles, Prime Meridian, Date Line) | Dated latitudes, line lengths, and land crossings were off — e.g. Tropic latitude 23.4394°, polar-circle length 15,966 km, Equator “touches US land”, Prime Meridian crossing ~4,500 km. | Recomputed to 1 Jan 2026 values with corrected crossings — 23.4359°, 15,984 km, no US land on the Equator, ~6,800 km of meridian over land. |
| Oct 2, 2026 | Geographic Center Finder | Covered 177 countries on Natural Earth 1:110m; several center points were wrong (US 2020 population center, France, UK, Africa). | Covers 241 countries/territories on 1:50m, with corrected centers and no false claim that an agency “marked” the US points. |
| Oct 2, 2026 | Antipode Finder & Map Tunnel | Antipodal distance stated as exactly π·R = 20,015 km; land-corridor and nearest-antipode-capital claims were inaccurate. | About 20,015 km (20,004–20,037 km on WGS-84); corrected land corridors and the Madrid–Wellington near-antipode. |
| Oct 1, 2026 | Size-comparison pages | Used US population 334.9M, Alaska 663,267 sq mi, and Canada’s coastline 151,485 mi (mixed NOAA/CIA basis). | US 341.8M (Census Vintage 2025), Alaska 665,384 sq mi, Canada’s coastline 125,567 mi on a consistent CIA basis; ratios recomputed. |
| Sep 30, 2026 | Methodology & study data source | Cited SimpleMaps v1.94 with “~41,000 ZCTAs”, Census ACS 2020, licence “public domain / paid”. | SimpleMaps v1.95.1 (8 Jul 2026), 33,782 populated ZCTAs, ACS 2024 5-year, free tier CC BY 4.0. |
| Sep 30, 2026 | State Capital Radius study | Tallahassee was 350 miles from Florida’s population centroid and Honolulu 5 miles from Hawaii’s. | Tallahassee 239 miles; Honolulu 28 miles (recomputed from the data). |
| Sep 30, 2026 | ZIP code lookup pages | “~41,700 ZIP codes”; notable-ZIP tiles with impossible figures; “export as PNG/SVG/PDF/GeoJSON”; wrong most/fewest-ZIP states. | 41,545 USPS ZIPs (33,782 ZCTAs with demographics); corrected notable-ZIP tiles; export described honestly; Texas/California most, Rhode Island/Delaware/Hawaii fewest. |
| Sep 30, 2026 | Population Within Radius | County/state/place counts were taken from the top-10 lists only (10001 @ 50 mi showed “10 counties, 2 states”). | Counts cover every ZCTA in the circle (10001 @ 50 mi = 27 counties, 3 states, 626 places). |
| Sep 30, 2026 | County Map with Cities | The largest-counties table used hand-typed “Cities” counts (Miami-Dade 80, Kings 12). | A “postal places” column driven from the county dataset by FIPS (Miami-Dade 9, Kings 1). |
| Sep 30, 2026 | Distance Between Cities | Example claimed Denver → Phoenix is 586 mi. | 583 mi. |
| Sep 30, 2026 | Sun tools | SunCalc was attributed to the NOAA/Meeus SPA with accuracy claims of ±0.01° / ±1 s; a Sydney example azimuth was off. | SunCalc’s formulas are credited to the Astronomy Answers articles, the unsupported NOAA accuracy claims removed, and the example corrected. |
| Sep 30, 2026 | What City Am I In | Called Tokyo the most populous city (~37.4M metro) and said 56% of the world lives in cities. | Jakarta is the most populous urban area (~42M, UN WUP 2025); about 45% live in cities. |
| Sep 30, 2026 | What County Am I In & largest-counties blog | San Bernardino County described as the largest US county by land area. | Largest in the contiguous US; several Alaska boroughs and census areas are larger. |
| Sep 30, 2026 | What State Am I In | Said 911 systems are state-administered. | 911 service is run locally by counties and cities; only agencies such as the state police are organized by state. |
| Sep 30, 2026 | Time Zone Finder | Stated the IANA tz database covers about 440 distinct time zones. | 419 distinct zones (the timezone-boundary-builder dataset the tool queries). |
| Sep 30, 2026 | World Time Zone Map | Called the largest time gap 26 hours between inhabited places. | 26 hours only to uninhabited UTC-12; the widest inhabited gap is 25 hours (UTC-11 to UTC+14). |
| Sep 30, 2026 | Elevation Finder | Gave Aspen, Colorado as 2,438 m / 8,000 ft. | 2,410 m / 7,908 ft. |
| Sep 30, 2026 | Find Elevation on Google Maps (guide) | Said Google Maps itself cannot draw an elevation profile. | Its cycling directions show an elevation chart (added July 2022); the dedicated tools remain the fuller route-profile option. |
| Sep 30, 2026 | Find Nearest National Park | Wrangell–St. Elias given as 13,175 sq mi, Gateway Arch 0.14 sq mi; Denver distances quoted as driving miles. | Wrangell–St. Elias 20,587 sq mi, Gateway Arch 0.30 sq mi; distances are straight-line. |
| Sep 30, 2026 | Country Size Comparison | Gave the Mercator area-inflation factor as sec φ (45° = 1.41×) and said Madagascar is smaller than France. | The factor is sec²φ (45° = 2.0×); Madagascar (587k km²) is larger than metropolitan France (551.7k km²). |
| Sep 30, 2026 | India vs USA | Said India is roughly the 13 largest US states combined and that Delhi is the world’s most populous urban area. | About the 5 largest US states combined; Delhi is not #1 (Jakarta, per UN WUP 2025). |
| Sep 30, 2026 | Alaska data (county pages & population post) | Alaska’s area was stored as 503,557 sq mi in the dataset and 663,300 sq mi in a blog post. | Alaska land area 570,641 sq mi; total area 665,384 sq mi. |
| Sep 25, 2026 | ZIP & city tools (licensing and centroids) | Described the SimpleMaps ZIP data as public domain / free for commercial use, and the coordinates as population-weighted centroids. | The ZIP data is used under a licence (not public domain); the coordinates are the geometric centroids of Census ZCTA polygons. |