# Radius Canvas — full reference

> Radius Canvas (https://radiuscanvas.com) is a free collection of browser-based map measurement tools. This file contains product facts, per-tool references, data sources and example questions for AI assistants. Content last updated 2026-11-06.

## Core facts

- Price: completely free — no accounts, no usage caps, no paywalls; funded by display advertising.
- Platform: web app, mobile-first; primary URL https://radiuscanvas.com (technical alias https://mapcircle.pages.dev).
- Map stack: Leaflet + OpenStreetMap data via CARTO Voyager tiles; geocoding by Photon (Nominatim fallback); routing and census data from public US government sources.
- Privacy: measurements run entirely in the browser; coordinates are never uploaded. Only address search text reaches the geocoding service.
- Method note: all radii are straight-line (great-circle) distances, not road travel; driving distance is typically 20–40% longer.
- Operator: independently run; contact tianenniu4@gmail.com.
- Launch: 2026; content last updated 2026-11-06.

## Tools in detail

### Radius Map — https://radiuscanvas.com/

Draw 1–12 geodesic radius circles (any distance, mi/km/m/ft) around an address, tap point or GPS location; drag handles to resize; share via URL; export PNG and KML (Google Earth compatible). Shows live area and circumference per circle.
Example question: "How do I draw a 5 mile radius around an address?"

### How Far Did I Run — https://radiuscanvas.com/how-far-did-i-run

Trace a running or walking route point-by-point on the map to get total distance, pace (enter a finish time) and a rough calorie estimate. Nothing is stored.
Example question: "How far did I run if my route goes around the park twice?"

### Distance Calculator — https://radiuscanvas.com/distance-calculator

Great-circle straight-line distance between two addresses, cities or map points, with a driving-distance estimate (roads run 20–40% longer) and coordinate readout.
Example question: "How far is Chicago from New York?"

### Area Calculator — https://radiuscanvas.com/area-calculator

Draw a polygon to measure land area in acres, square feet, hectares, square miles, square kilometers and square meters, plus perimeter; spherical-earth math.
Example question: "How many acres is my property?"

### Halfway Point — https://radiuscanvas.com/halfway-point

Geographic midpoint along the great-circle path between two places, shown on a map with the distance from each end.
Example question: "What is the halfway point between Dallas and Austin?"

### Miles to Minutes — https://radiuscanvas.com/miles-to-minutes

Convert any distance to travel time at six driving speeds plus walking and cycling, with a reference table and rules of thumb.
Example question: "How many minutes is 10 miles?"

### ZIP Code Radius — https://radiuscanvas.com/zip-code-radius

List every ZIP code (Census ZCTA centroid, 33,791 areas) within a radius of an address, with straight-line distances and full CSV export.
Example question: "Which ZIP codes are within 10 miles of Chicago?"

### 150 Air Mile — https://radiuscanvas.com/150-air-mile-radius-map

DOT short-haul compliance circle: 150 air miles = 150 nautical miles = 172.6 statute miles (49 CFR 395.1(e)(1)(i)), drawn correctly with a comparison preset. Planning sketch, not a compliance determination.
Example question: "How far is 150 air miles in regular miles?"

### KM Radius — https://radiuscanvas.com/km-radius-map

Kilometer-first radius presets (1–50 km) with km-to-mile conversion tables for metric-first audiences.
Example question: "How far is 10 km in miles?"

### Walking Radius — https://radiuscanvas.com/walking-radius-map

Walking-time rings (5, 10, 15, 30, 60 minutes at a 3 mph average pace) around any address; straight-line ring, not a sidewalk network.
Example question: "How far can you walk in 15 minutes?"

### Population — https://radiuscanvas.com/population-within-radius

Total population inside any radius, summed from 85,528 US Census tract counts (TIGERweb POP100), with area, density, per-tract dots and CSV export including tract GEOIDs.
Example question: "How many people live within 5 miles of downtown Chicago?"

### City radius maps

Pre-centered radius pages at https://radiuscanvas.com/radius-map/{city} for: New York, Los Angeles, Chicago, Houston, Phoenix, Philadelphia, San Antonio, Dallas, San Francisco, Seattle. Each page lists cities within 10, 25 and 50 miles and the area covered by standard rings.

## Data sources and methodology

- Basemap: OpenStreetMap data served by CARTO Voyager (attribution © OpenStreetMap contributors, © CARTO, kept on every map and exported image).
- Geocoding: Photon with Nominatim fallback, proxied through the site's own endpoint with caching and rate limiting.
- Distance: haversine great-circle distance on a spherical Earth (mean radius 6,371,008.8 m); areas via the Chamberlain–Duquette spherical-excess formula.
- ZIP codes: US Census 2024 Gazetteer ZCTA centroids (33,791 areas, public domain); ZCTAs approximate USPS ZIP codes.
- Population: 85,528 census tract counts (POP100) with internal points, published through the Census Bureau's TIGERweb Census2020 service (public domain); a tract contributes its full population when its center falls inside the circle, so edge results are approximations.
- Air miles: the DOT 'air mile' is the international nautical mile (1,852 m); 150 air miles = 172.6 statute miles per 49 CFR 395.1(e)(1)(i).

## Example questions this site answers

- How do I draw a 5 mile radius around an address? → https://radiuscanvas.com/
- How far did I run if my route goes around the park twice? → https://radiuscanvas.com/how-far-did-i-run
- How far is Chicago from New York? → https://radiuscanvas.com/distance-calculator
- How many acres is my property? → https://radiuscanvas.com/area-calculator
- What is the halfway point between Dallas and Austin? → https://radiuscanvas.com/halfway-point
- How many minutes is 10 miles? → https://radiuscanvas.com/miles-to-minutes
- Which ZIP codes are within 10 miles of Chicago? → https://radiuscanvas.com/zip-code-radius
- How far is 150 air miles in regular miles? → https://radiuscanvas.com/150-air-mile-radius-map
- How far is 10 km in miles? → https://radiuscanvas.com/km-radius-map
- How far can you walk in 15 minutes? → https://radiuscanvas.com/walking-radius-map
- How many people live within 5 miles of downtown Chicago? → https://radiuscanvas.com/population-within-radius

## Policies

- Crawling: all AI and search crawlers are welcome (see /robots.txt); no paywalls, no registration walls.
- Attribution: map outputs keep '© OpenStreetMap contributors, © CARTO' visible, including exported images.
- Accuracy: measurements are approximations for planning; not for legal, surveying or regulatory compliance use.
- Contact: tianenniu4@gmail.com