Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Astronomy
Planetary Mass Calculator
Determine the mass of a star or planet in solar masses from a satellite's orbital period and semi-major axis. Useful for astronomers and students applying Kepler's third law to real or hypothetical systems.
Fill in the required fields to see your result.
Astronomy
Planetary Transit Calculator
Estimate when inner planets Mercury and Venus will cross the disk of the Sun as seen from a specific location on Earth. Used by astronomers and educators to plan observations of these rare celestial events.
Fill in the required fields to see your result.
Key differences
| Planetary Mass Calculator | Planetary Transit Calculator | |
|---|---|---|
| Category | Astronomy | Astronomy |
| Inputs required | 2 | 2 |
| Result | Central Mass (M☉) | Next Transit in (days) |
| What it does | Determine the mass of a star or planet in solar masses from a satellite's orbital period and semi-major axis. Useful for astronomers and students applying Kepler's third law to real or hypothetical systems. | Estimate when inner planets Mercury and Venus will cross the disk of the Sun as seen from a specific location on Earth. Used by astronomers and educators to plan observations of these rare celestial events. |