Distance Calculator FAQ

Question 1

What does "as the crow flies" mean?

Accepted Answer

"As the crow flies" refers to the straight-line distance between two points on Earth's surface, ignoring any obstacles like mountains, buildings, or bodies of water. It's the shortest possible distance between two locations on our planet, calculated along what's called a "great circle" route. The phrase originates from the observation that crows fly directly to their destination, unlike humans who must follow roads and paths.

Question 2

How do I calculate the distance between two cities?

Accepted Answer

You can calculate distances using several methods on our website: (1) Use the search boxes to type city names and select from our autocomplete suggestions, (2) Click directly on the interactive map to set Point A and Point B, (3) Use the GPS button to set your current location as one point, or (4) Choose from our list of 100 popular city pairs. Once you set both points, the distance is calculated instantly using the Haversine formula.

Question 3

Can I use my current GPS location?

Accepted Answer

Yes! Click the GPS button next to either search box to use your current location. Your browser will ask for permission to access your location. This feature works on both desktop and mobile devices. Your location data is processed only in your browser and never transmitted to our servers for privacy protection.

Question 4

What cities are included in your database?

Accepted Answer

Our database includes thousands of cities worldwide, covering major metropolitan areas, regional centers, and significant towns across all continents. We focus on cities with populations over 15,000 people, plus important smaller locations that are frequently searched. The database includes accurate latitude and longitude coordinates for precise calculations.

Question 5

How accurate are your distance calculations?

Accepted Answer

Our calculations use the Haversine formula with Earth's radius of 6,371 kilometers (3,959 miles), providing accuracy within 0.5% for most practical purposes. We assume Earth is a perfect sphere, which is a close approximation. The actual Earth is an oblate spheroid (slightly flattened at the poles), but this difference is negligible for typical city-to-city distances. For surveying or aviation applications requiring higher precision, consider using ellipsoidal calculations.

Question 6

What is the Haversine formula and why do you use it?

Accepted Answer

The Haversine formula calculates great-circle distances between two points on a sphere given their latitude and longitude coordinates. We use it because it accounts for Earth's spherical shape, unlike simple Euclidean distance formulas that work only on flat surfaces. The formula: d = 2r × arcsin(√(sin²(Δφ/2) + cos(φ₁) × cos(φ₂) × sin²(Δλ/2))), where d is distance, r is Earth's radius, φ represents latitudes, and λ represents longitudes.

Question 7

Why do my calculations show different results from other websites?

Accepted Answer

Small differences can occur due to: (1) Different Earth radius values used (we use 6,371 km, some use 6,378 km), (2) Different coordinate precision for cities, (3) Whether the calculation uses spherical vs. ellipsoidal Earth models, (4) Rounding differences in the final result. Most reputable calculators should agree within 1-2% for typical distances.

Question 8

Do you calculate driving or flying distances?

Accepted Answer

No, we calculate only straight-line distances "as the crow flies." These represent the theoretical shortest distance on Earth's surface and are always shorter than actual travel distances. Driving distances follow roads and can be 30-100% longer. Flying distances follow air traffic routes and weather patterns, typically 5-15% longer than straight-line distances. Our comprehensive results do provide estimated travel times for context.

Question 9

Why is the straight-line distance shorter than actual travel distance?

Accepted Answer

Straight-line distance represents the theoretical minimum distance on Earth's surface, while actual travel must account for physical constraints: roads follow terrain and avoid obstacles, ships must navigate around landmasses, and planes follow air traffic control routes and avoid restricted airspace. Additionally, our spherical Earth means the shortest path often goes over polar regions, which isn't practical for most transportation.

Question 10

What do the bearing and direction information mean?

Accepted Answer

Bearing is the initial compass direction (0-360 degrees) you would need to travel from the starting point toward the destination along the great circle route. Direction translates this into common compass terms (N, NE, E, SE, S, SW, W, NW). Note that along a great circle route, the bearing changes continuously except when traveling due north, south, or along the equator.

Question 11

How do you estimate flight and travel times?

Accepted Answer

Our estimates are rough approximations: Flight times assume an average commercial aircraft speed of 500 mph, driving times assume 60 mph average including stops and traffic, walking assumes 3 mph, and sailing assumes 10 mph. These are for comparison purposes only. Actual travel times vary significantly based on routes, weather, traffic, connections, and transportation method.

Question 12

What are the comparison facts in my results?

Accepted Answer

We provide contextual comparisons to help you understand the scale of distances, such as "similar to the distance from New York to Chicago" or "equivalent to crossing Texas." These comparisons use well-known geographical references and are based on commonly understood distances. They help put abstract numbers into relatable terms.

Question 13

Why do flight paths look curved on flat maps?

Accepted Answer

Flight paths appear curved on flat maps due to map projection distortions. The shortest path between two points on a sphere (great circle route) appears as a straight line only on a globe. When this spherical surface is projected onto a flat map, these straight lines become curves. This is why flights from New York to Tokyo go over Alaska rather than straight across the Pacific—it's actually the shorter route on our spherical Earth.

Question 14

What is a great circle route?

Accepted Answer

A great circle is the largest possible circle that can be drawn on a sphere, formed where a plane passing through the sphere's center intersects the surface. The shortest distance between any two points on a sphere lies along the great circle connecting them. Examples include the equator and all meridians (longitude lines), but not latitude lines (except the equator).

Question 15

Why does Greenland look so large on maps?

Accepted Answer

Most world maps use the Mercator projection, which preserves angles but severely distorts areas near the poles. Greenland appears larger than Africa on Mercator maps, but Africa is actually 14 times larger! This distortion affects our perception of distances and explains why polar routes often seem impossibly indirect when they're actually the shortest paths.

Question 16

How do you handle locations near the International Date Line?

Accepted Answer

The International Date Line creates challenges for longitude calculations since it represents a discontinuity from +180° to -180°. Our calculations account for this by determining whether the shorter path crosses the date line and adjusting the longitude difference accordingly. This ensures accurate distances for trans-Pacific routes.

Question 17

When would I need to know straight-line distances?

Accepted Answer

Straight-line distances are useful for: (1) Radio communication planning (signals travel in straight lines), (2) Aviation fuel planning and initial route estimation, (3) Understanding time zone changes and jet lag, (4) Shipping and logistics cost estimation, (5) Emergency evacuation planning, (6) Understanding geographical relationships, (7) Academic research in geography or mathematics, (8) General curiosity about world geography.

Question 18

Can businesses use this for logistics planning?

Accepted Answer

While our tool provides valuable initial estimates, businesses should use specialized logistics software for actual planning. Our distances help with preliminary analysis, cost estimation, understanding market reach, and geographic analysis. However, actual shipping routes, customs procedures, infrastructure availability, and transportation networks require specialized tools and professional consultation.

Question 19

How accurate is this for amateur radio communications?

Accepted Answer

Very accurate! Radio waves travel along great circle paths, making our calculations directly applicable to amateur radio. The bearing information helps aim directional antennas, and the distance helps estimate signal propagation. Many ham radio operators use great circle maps similar to our calculations for long-distance communication planning.

Question 20

Can I use this for educational purposes?

Accepted Answer

Absolutely! Our tool is perfect for geography lessons, mathematics education, and general learning about world geography. Teachers can use it to demonstrate map projections, spherical geometry, and global distances. Students can explore surprising geographical relationships and understand why the world isn't quite as it appears on flat maps.

Question 21

Do you track or store my searches?

Accepted Answer

No, we don't track individual searches or store personal data. Distance calculations happen entirely in your browser using JavaScript, so your search queries never leave your device. We may collect anonymized analytics about page views and general usage patterns, but we never track what specific cities or coordinates you search for.

Question 22

Do I need to create an account?

Accepted Answer

No account is required! Our service works completely without registration. You can calculate unlimited distances, access all features, and read our educational content without providing any personal information. This makes our tool accessible to everyone while protecting your privacy.

Question 23

Is this service free?

Accepted Answer

Yes, CrowFliesDistance.com is completely free for personal, educational, and non-commercial use. There are no hidden fees, premium features, or usage limits. We believe geographical education and distance calculation tools should be accessible to everyone.

Question 24

Can I link to your website or specific calculations?

Accepted Answer

Yes! You're welcome to link to our homepage, blog articles, or specific city pair calculations. We encourage sharing links for educational purposes. The URLs are designed to be permanent and shareable. However, please don't reproduce large portions of our content without attribution.

Question 25

The map isn't loading or responding to clicks

Accepted Answer

This usually indicates a JavaScript or connectivity issue. Try: (1) Refreshing the page, (2) Checking your internet connection, (3) Disabling browser extensions that might block scripts, (4) Trying a different browser, (5) Clearing your browser cache. The map requires JavaScript to be enabled to function properly.

Question 26

My city doesn't appear in the search results

Accepted Answer

If your city isn't found, try: (1) Different spellings or abbreviations, (2) Including the country name, (3) Trying the nearest major city, (4) Using the map click feature to select the approximate location manually. Our database focuses on cities with populations over 15,000, so very small towns might not be included.

Question 27

The GPS location feature isn't working

Accepted Answer

GPS issues are usually related to browser permissions or device capabilities. Ensure: (1) You've granted location permission when prompted, (2) Your device has GPS or location services enabled, (3) You're using HTTPS (required for location access), (4) You're not using a VPN that might mask your location. Location accuracy depends on your device and environment.

Question 28

I'm getting obviously wrong results

Accepted Answer

Wrong results usually indicate: (1) You selected the wrong city from autocomplete suggestions (check for cities with the same name in different countries), (2) Coordinate data error in our database, (3) Confusion between different measurement units. Double-check your selected cities and contact us if you believe there's an error in our data.

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