Planetary Calculators — Astronomy
10 free planetary calculators in astronomy & space science. Each tool shows step-by-step formulas, worked examples, and detailed explanations to help you get accurate results instantly.
All Planetary Calculators
Calculate the energy and crater size of a hypothetical asteroid impact from mass and velocity.
Calculate the dates and visibility of upcoming solar and lunar eclipses for your location.
Calculate the current moon phase and upcoming full and new moon dates.
Calculate your weight on any planet in the solar system based on surface gravity.
Calculate delta-v from the Tsiolkovsky rocket equation using mass ratio and exhaust velocity.
Calculate scaled distances and sizes for a solar system scale model at any chosen scale.
Estimate space mission costs from payload mass, orbit, and launch vehicle selection.
Calculate breathable air supply duration for EVA from tank pressure, volume, and consumption rate.
Calculate the distance to a star from its parallax angle in parsecs and light years.
Calculate sunrise, sunset, and daylight hours for any location and date on Earth.
About Planetary Calculators
Our planetary calculators in astronomy & space science are designed for students, professionals, and anyone who needs quick, accurate results. Every calculator includes the underlying formula, step-by-step solutions, and real-world worked examples so you can understand the math behind the answer.
Whether you need to solve a one-time problem or verify your own calculations, these free tools cover the most common planetary scenarios. All results are computed in your browser — no data is sent to any server.
What You Can Calculate
This section includes 10 tools: Asteroid Impact Calculator, Eclipse Calculator, Moon Phase Calculator, Planet Weight Calculator, Rocket Equation Calculator, Solar System Scale Model Calculator, Space Mission Cost Calculator, Space Suit Air Supply Calculator, and 2 more. Each calculator is free to use with no signup required.