How to Use Schwarzschild Radius Calculator
Enter the mass of the object in kilograms. You can use ordinary decimal notation or scientific notation, such as 5.972e24 for Earth mass or 1.989e30 for solar mass.
Calculate to see the Schwarzschild radius in meters and kilometers. The value answers a specific theoretical question: how small the mass would need to be compressed for the escape velocity at that radius to reach the speed of light.
Use the supporting mass row to confirm that the input was interpreted correctly. For very large or very small values, scientific notation is usually the cleanest way to avoid missing zeros.
Formula & Theory - Schwarzschild Radius Calculator
The Schwarzschild Radius Calculator uses Rs = 2GM/c². G is the gravitational constant, approximately 6.674 × 10^-11 m³ kg^-1 s^-2. M is mass in kilograms. c is the speed of light in meters per second, about 299,792,458 m/s.
The formula describes a non-rotating, uncharged black hole in general relativity. Real astrophysical black holes can rotate, and rotation changes horizon geometry, but the Schwarzschild radius remains the standard first calculation for understanding the mass-to-radius scale of a black hole.
Use Cases for Schwarzschild Radius Calculator
- Compare the event-horizon scale of Earth, the Sun, or a compact object.
- Demonstrate how mass controls black hole radius in physics lessons.
- Check astronomy examples without doing repeated scientific-notation arithmetic by hand.