1. What is Distance Per Degree Longitude?

The distance covered by one degree of longitude varies depending on latitude. While lines of latitude are always equally spaced (about 111 km apart), longitude lines converge at the poles. This calculator determines how many kilometers correspond to one degree of longitude at a specific latitude.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• 111.32 km — Distance per degree of latitude (constant)
• cos(latitude) — Cosine of the latitude in degrees

Explanation: The cosine function accounts for the convergence of longitude lines as you move toward the poles. At the equator (0° latitude), one degree of longitude equals approximately 111.32 km. This distance decreases to 0 at the poles (90° latitude).

3. Importance of This Calculation

Details: Understanding distance per degree longitude is essential for navigation, mapping, GPS systems, and any application that requires accurate distance measurements across different latitudes.

4. Using the Calculator

Tips: Enter the latitude in degrees (between -90 and 90). Positive values are for northern hemisphere, negative for southern hemisphere.

5. Frequently Asked Questions (FAQ)

Q1: Why does distance per degree longitude vary?
A: Because the Earth is a sphere, longitude lines converge at the poles, making the distance between them decrease as you move away from the equator.

Q2: What's the distance at the equator?
A: Approximately 111.32 km per degree longitude at 0° latitude (the equator).

Q3: What's the distance at 45° latitude?
A: About 78.71 km per degree longitude (111.32 × cos(45°)).

Q4: Is this calculation perfectly accurate?
A: It provides a good approximation, though the Earth is slightly ellipsoidal which creates minor variations.

Q5: How is this used in real-world applications?
A: Used in navigation systems, map projections, GIS software, and calculating distances between coordinates.