Schwarzschild Radius Calculator

Calculate the event horizon (Schwarzschild radius) of a black hole for any mass. Visualize what happens when the Sun or Earth collapses.

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Black hole calculator — calculate Schwarzschild radius (event horizon) for any mass. Kala chhedra ka aakar. Sun, Earth, or stellar objects. Free.

How to Use Schwarzschild Radius Calculator — Step by Step

  1. 1Enter the mass of the object
  2. 2Select the unit — solar masses, Earth masses, or kg
  3. 3Click 'Calculate Schwarzschild Radius'
  4. 4View the event horizon size in meters or km
  5. 5Compare with known black holes in the reference table

Why Use ToolNest for Schwarzschild Radius Calculator?

  • Formula: r_s = 2GM/c² — exact general relativistic result
  • 🌟Input in solar masses, Earth masses, or kg
  • 📊Reference table: Sun, Earth, stellar BH, and Sagittarius A*
  • 💡Shows average density inside the event horizon
  • 🆓Perfect for physics students and curious space enthusiasts

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Frequently Asked Questions

What is the Schwarzschild radius?

The Schwarzschild radius is the radius at which a mass must be compressed for it to become a black hole (event horizon). For any mass M, r_s = 2GM/c². For the Sun, this is about 3 km.

What is the Schwarzschild radius of Earth?

Earth's Schwarzschild radius is about 8.87 mm — roughly the size of a marble. If Earth were compressed to that size, it would become a black hole.

Can the Sun become a black hole?

Not naturally — the Sun is too low-mass. When it dies in about 5 billion years, it will expand into a red giant and then collapse to a white dwarf. Only stars above about 20 solar masses form black holes.

Is the Schwarzschild radius the same as event horizon?

For a non-rotating black hole, yes. The Schwarzschild radius defines the event horizon — the boundary of no return. Rotating black holes (Kerr metric) have a more complex structure with an ergosphere.