The short answer: Stellar black holes typically weigh between 5 and 20 times the mass of the Sun (about 1 x 10^31 to 4 x 10^31 kilograms), while supermassive black holes can weigh millions to billions of solar masses. Their mass depends on how much matter they have absorbed.
Black hole weight by type
Black holes span an enormous range of masses, from a few solar masses to billions. Their weight is inferred from how they affect the motion of nearby stars and gas.
| Black hole type (example) | Approximate mass |
|---|---|
| Stellar black hole | about 5-20 solar masses |
| Intermediate-mass black hole | hundreds to thousands of solar masses |
| Supermassive (typical galaxy) | millions of solar masses |
| Largest supermassive black holes | billions of solar masses |
What affects black hole weight
- Formation. Collapsing massive stars create stellar-mass black holes.
- Accretion. Black holes grow by pulling in surrounding gas and dust.
- Mergers. Black holes combine to form much more massive ones.
- Host environment. Galactic centers hold the most massive black holes.
- Time. Older black holes have had longer to accumulate mass.
- Measurement method. Mass is inferred from orbiting stars, gas motion, or gravitational waves.
How black hole weight compares
The smallest stellar black holes already pack several Suns into a region smaller than a city, while the supermassive black hole at the Milky Way's center weighs about 4 million Suns.
Frequently asked questions
How do scientists weigh a black hole?
They measure how the black hole's gravity affects nearby stars and gas, or analyze gravitational waves from mergers, to infer its mass.
What is the difference between stellar and supermassive black holes?
Stellar black holes form from collapsed stars and weigh a few to dozens of solar masses, while supermassive ones at galaxy centers weigh millions to billions of solar masses.
How heavy is the black hole in our galaxy?
The supermassive black hole at the center of the Milky Way, Sagittarius A*, weighs roughly 4 million times the mass of the Sun.
