Science calculator
Kepler's Third Law Calculator
Calculate orbital period from semi-major axis.
About the kepler's third law calculator
Kepler's third law calculator computes orbital period from semi-major axis and central body mass.
How to use this calculator
- 1
Enter semi-major axis
Enter the orbital distance in AU.
- 2
Enter central mass
Enter the central body's mass in solar masses (1 for Sun by default).
- 3
View results
See the orbital period in Earth years.
How the calculation works
T² = a³/M (in Earth years, AU, solar masses).
Example: a=1AU, M=1: T=1 year. a=5.2AU (Jupiter): T≈11.9yr.
Understanding scientific constants
Key constants used: g = 9.81 m/s² (Earth gravity), c = 299,792,458 m/s (speed of light), G = 6.674×10⁻¹¹ N·m²/kg² (gravitational constant), h = 6.626×10⁻³⁴ J·s (Planck's constant), R = 8.314 J/(mol·K) (ideal gas constant). Results assume ideal conditions — real-world measurements may vary.
Ideal vs. real-world conditions
Most physics calculators assume ideal conditions: no air resistance, perfect vacuums, uniform gravity. Real-world results will differ due to friction, air resistance, temperature variations, and measurement uncertainty. Use these tools for learning and estimation, not precision engineering.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, market conditions, or individual circumstances. Results are for planning purposes only — consult a qualified professional for regulated, medical, financial, or construction decisions.
Frequently asked questions about kepler's third law calculator
How accurate is the keplers law calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.