Decimal Degrees to Km Calculator

This calculator converts decimal degrees of latitude and longitude to kilometers. It's useful for calculating distances between geographic coordinates, determining the size of areas, or understanding spatial relationships in mapping and navigation applications.

How to Use This Calculator

To convert decimal degrees to kilometers:

Enter the starting latitude and longitude coordinates in decimal degrees.
Enter the ending latitude and longitude coordinates in decimal degrees.
Click the "Calculate" button to see the distance in kilometers.
The result will appear in the green result box below the calculator.

The calculator uses the Haversine formula to provide accurate distance calculations between two points on the Earth's surface.

Formula Explained

The distance between two points on the Earth's surface can be calculated using the Haversine formula:

Haversine Formula

a = sin²(Δφ/2) + cos φ1 ⋅ cos φ2 ⋅ sin²(Δλ/2)

c = 2 ⋅ atan2(√a, √(1−a))

d = R ⋅ c

Where:

φ is latitude, λ is longitude
R is Earth's radius (mean radius = 6,371 km)
Δφ and Δλ are differences in latitude and longitude

This formula accounts for the Earth's curvature and provides accurate distance measurements between geographic coordinates.

Worked Examples

Let's calculate the distance between two points:

Example 1

Starting point: 40.7128° N, 74.0060° W (New York City)

Ending point: 34.0522° N, 118.2437° W (Los Angeles)

Using the Haversine formula, the calculated distance is approximately 3,935.75 km.

Example 2

Starting point: 51.5074° N, 0.1278° W (London)

Ending point: 48.8566° N, 2.3522° E (Paris)

Using the Haversine formula, the calculated distance is approximately 343.60 km.

Note

The actual distance may vary slightly due to the Earth's ellipsoidal shape and local terrain variations.

Frequently Asked Questions

What is the difference between decimal degrees and degrees, minutes, seconds?

Decimal degrees represent latitude and longitude as a single decimal number, while degrees, minutes, seconds break them into degrees, minutes, and seconds. This calculator works with decimal degrees for simplicity and precision.

Can I use this calculator for large distances?

Yes, the Haversine formula works well for both short and long distances, providing accurate results across the entire Earth's surface.

What is the Earth's radius used in the calculation?

The calculator uses the mean radius of the Earth (6,371 km), which provides a good approximation for most distance calculations.