How to use the escape velocity calculator
Find the speed needed to escape a planet's gravity. Enter mass, radius in the fields above; the escape velocity, escape velocity are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- M — Mass (kg)
- r — Radius (km)
Worked example
With mass = 5.9722e24 kg, radius = 6371 km, the calculator gives escape velocity ≈ 11.18617 km/s; escape velocity ≈ 40,270.19 km/h.
Frequently asked questions
What is the formula for the escape velocity calculation?
Escape velocity (km/s) = √(2 × GCONST × M / (r × 1000)) / 1000. Escape velocity (km/h) = [Escape velocity] × 3600. Here M is mass (kg), r is radius (km).
What inputs do I need for the escape velocity calculator?
You need mass in kg, radius in km. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.