Great-Circle Distance Calculator & How to Calculate Distance Using Google Maps
This calculator estimates the great-circle (shortest distance over the Earth’s surface) between two points using their latitude and longitude. It’s useful for understanding the base distance before considering routes. Below, we also discuss how to calculate distance using Google Maps for actual travel routes.
Great-Circle Distance Calculator
Enter degrees, -90 to 90 (e.g., 40.7128 for New York)
Enter degrees, -180 to 180 (e.g., -74.0060 for New York)
Enter degrees, -90 to 90 (e.g., 34.0522 for Los Angeles)
Enter degrees, -180 to 180 (e.g., -118.2437 for Los Angeles)
Delta Latitude (rad): N/A
Delta Longitude (rad): N/A
Haversine ‘a’: N/A
Haversine ‘c’: N/A
Earth Radius: 6371 km
a = sin²(Δφ/2) + cos φ1 ⋅ cos φ2 ⋅ sin²(Δλ/2)
c = 2 ⋅ atan2( √a, √(1−a) )
Distance = R ⋅ c
(where φ is latitude, λ is longitude, R is Earth’s radius, Δφ=φ2-φ1, Δλ=λ2-λ1, all angles in radians)
Chart comparing distance in Kilometers and Miles.
| Parameter | Value |
|---|---|
| Point 1 Latitude | N/A |
| Point 1 Longitude | N/A |
| Point 2 Latitude | N/A |
| Point 2 Longitude | N/A |
| Distance (km) | N/A |
| Distance (miles) | N/A |
| Distance (nautical miles) | N/A |
Summary of input coordinates and calculated distances.
What is Calculating Distance Using Google Maps?
To calculate distance using Google Maps means using Google’s mapping service to determine the length of a route between two or more points. Unlike the great-circle distance calculated above (which is the shortest distance on the Earth’s surface), Google Maps typically provides driving, walking, cycling, or transit distances, which follow actual roads, paths, or transit lines. These distances are almost always longer than the great-circle distance.
People use Google Maps to calculate distances for trip planning, estimating travel time, calculating fuel costs, logistics, and simply measuring how far one place is from another via a specific mode of transport.
A common misconception is that the distance shown on Google Maps is always the absolute shortest distance. In reality, it’s the shortest practical route based on the selected mode of transport and available infrastructure, which can be affected by one-way streets, traffic conditions (for time estimates), and road closures. Our calculator above gives the ‘as the crow flies’ distance, useful for aviation or a baseline, while Google Maps gives route-based distances.
Great-Circle Distance Formula and Mathematical Explanation
The calculator above uses the Haversine formula to determine the great-circle distance between two points on a sphere (approximating the Earth) given their longitudes and latitudes. This is the shortest distance over the Earth’s surface, ignoring terrain and routes.
The steps are:
- Convert latitude and longitude of both points from degrees to radians.
- Calculate the difference in latitude (Δφ) and longitude (Δλ) in radians.
- Calculate ‘a’: a = sin²(Δφ/2) + cos φ1 ⋅ cos φ2 ⋅ sin²(Δλ/2)
- Calculate ‘c’: c = 2 ⋅ atan2( √a, √(1−a) )
- Calculate Distance: d = R ⋅ c, where R is the Earth’s mean radius (approx. 6371 km).
Variables Table
| Variable | Meaning | Unit | Typical Range (for calculator) |
|---|---|---|---|
| φ1, φ2 (lat1, lat2) | Latitude of point 1 and 2 | Degrees | -90 to +90 |
| λ1, λ2 (lon1, lon2) | Longitude of point 1 and 2 | Degrees | -180 to +180 |
| Δφ, Δλ | Difference in latitude and longitude | Radians | -π to +π |
| R | Earth’s mean radius | Kilometers | 6371 km |
| d | Great-circle distance | Kilometers | 0 to ~20000 km |
Variables used in the Haversine formula for great-circle distance calculation.
While this is useful, remember that to calculate distance using Google Maps for driving, it involves complex algorithms considering road networks, speed limits, and traffic.
Practical Examples (Real-World Use Cases)
Example 1: New York to Los Angeles
Let’s use the default values: New York (40.7128° N, 74.0060° W) to Los Angeles (34.0522° N, 118.2437° W).
- Input Lat1: 40.7128, Lon1: -74.0060
- Input Lat2: 34.0522, Lon2: -118.2437
- Output Great-Circle Distance: Approx. 3936 km or 2446 miles.
If you ask Google Maps for driving directions, the distance is significantly longer (around 4500 km or 2800 miles) because roads don’t follow a perfect arc.
Example 2: London to Paris
London (51.5074° N, 0.1278° W) to Paris (48.8566° N, 2.3522° E).
- Input Lat1: 51.5074, Lon1: -0.1278
- Input Lat2: 48.8566, Lon2: 2.3522
- Output Great-Circle Distance: Approx. 344 km or 214 miles.
The driving distance via Google Maps (using the Channel Tunnel) is around 450-470 km, again longer than the direct line. When you calculate distance using Google Maps, it accounts for the actual travel path.
How to Use This Great-Circle Distance Calculator
- Enter Coordinates: Input the latitude and longitude for your starting point (Point 1) and destination (Point 2) in decimal degrees. North latitudes and East longitudes are positive, South and West are negative.
- View Results: The calculator will instantly show the great-circle distance in kilometers and miles, along with intermediate Haversine values. The chart and table also update.
- Interpret: This is the shortest distance over the Earth’s surface. Actual travel distance using roads will be longer.
To calculate distance using Google Maps for driving, walking, or cycling:
- Go to Google Maps (maps.google.com).
- Enter your starting point and destination.
- Click “Directions” and select your mode of transport. Google Maps will show the route and distance. You can even right-click on the map and select “Measure distance” to draw a path and find its length. See our map coordinates finder for help with coordinates.
Key Factors That Affect Distance Calculation
When you calculate distance using Google Maps or compare it with our calculator, several factors influence the result:
- Great-Circle vs. Route Distance: Our calculator gives the shortest path on the globe. Google Maps provides distance along roads, paths, or transit lines, which are rarely straight.
- Mode of Transport: Driving, walking, and cycling routes differ, leading to different distances even between the same two points.
- Road Network & One-Way Streets: Google Maps considers the actual road layout, including one-way streets, which can make the route longer than a straight line.
- Earth’s Shape: The Earth is not a perfect sphere (it’s an oblate spheroid). While our calculator uses a mean radius, precise calculations might use a more complex model. Google Maps’ internal models are very sophisticated.
- Real-time Traffic and Closures: Google Maps can adjust routes and estimated travel times based on current traffic and road closures, although the distance of the chosen route itself usually remains fixed unless re-routed. For travel time, consider our driving time calculator.
- Route Preferences: Google Maps might offer routes avoiding highways or tolls, which can alter the distance.
- Intermediate Waypoints: Adding stops between the start and end points will increase the total distance calculated by Google Maps. Check out our route planner tool.
Frequently Asked Questions (FAQ)
It’s very accurate for the great-circle distance on a spherical Earth model. For most practical purposes, the difference from using a more complex ellipsoid model is small over moderate distances.
This calculator gives the shortest distance over the Earth’s surface (‘as the crow flies’). Google Maps gives the distance along actual roads or paths, which are longer. To calculate distance using Google Maps is to find route distance, not geometric shortest distance.
No, this calculator only provides the great-circle distance. For driving directions and distance, you need to use Google Maps directly.
You can right-click on a location in Google Maps, and the coordinates will be displayed and can be copied. Or use tools like our map coordinates finder.
The primary result is in kilometers (km), with conversions to miles (mi) and nautical miles (nm) also shown.
No, this calculator is for two points. For multi-point routes, you’d use Google Maps or a dedicated route planner tool.
No, it assumes a smooth spherical Earth and calculates the distance along the surface arc.
Google Maps uses pedestrian pathways, sidewalks, and road networks suitable for walking, factoring in things like pedestrian bridges and crossings, to calculate distance using Google Maps for walkers.
Related Tools and Internal Resources
- Driving Time Calculator: Estimate travel time based on distance and average speed.
- Fuel Cost Calculator: Calculate fuel expenses for your trip based on distance and vehicle efficiency.
- Route Planner Tool: Plan routes with multiple stops.
- Map Coordinates Finder: Easily find latitude and longitude for any location.
- Travel Budget Calculator: Plan your travel expenses.
- How to Use Google Maps Effectively: Tips and tricks for getting the most out of Google Maps, including how to calculate distance using Google Maps accurately.