Escape Velocity Calculator
Calculate escape velocity for a planet, moon, or star.
Check Escape Velocity Calculator
Formula result
Check before you use it
What the numbers show
The answer estimates the threshold speed needed to avoid falling back in the ideal no-loss model.
Use escape velocity calculator for planetary comparison, spaceflight intuition, and gravity-energy baselines.
Escape velocity depends on both mass and radius, not mass alone.
Copy-ready formula handoff
Use this after solving the live calculator result, then paste the answer into a lab note, homework check, or engineering review.
ve = sqrt(2 * G * M / r)
- Escape velocity: Minimum ideal launch speed needed to escape without more thrust.
- Body mass: Mass of the planet, moon, or star.
- Radius from center: Distance from the center of the body at launch.
- Atmospheric drag and planetary rotation are ignored.
- The launch is treated as an energy problem in the ideal gravitational field.
- Entering altitude above the surface instead of radius from the body center.
- Reading escape velocity as a rocket delta-v budget; drag, gravity losses, staging, and trajectory are outside this formula.
Escape Velocity Calculator result: [paste the solved value from the calculator above]. Formula used: ve = sqrt(2 * G * M / r) Inputs checked: Escape velocity, Body mass, Radius from center. Assumptions: Atmospheric drag and planetary rotation are ignored. The launch is treated as an energy problem in the ideal gravitational field. Worked example: Estimate escape speed from a planet with known mass and radius. Enter the body mass and radius. Apply ve = sqrt(2GM/r). Review the result in m/s or km/s as a baseline, not a full launch requirement. Next check: Entering altitude above the surface instead of radius from the body center.
Equation context
Built for planetary comparison, spaceflight intuition, and gravity-energy baselines. This page pairs the live calculator with the governing formula, variable glossary, and a worked example so the result is easier to trust and reuse.
Quick entry points
Use the calculator to verify arithmetic after you set up the formula yourself.
Change one input at a time to see which variable is driving the result.
Review the formula notes before using the answer in a lab or design check.
Variables to track
Minimum ideal launch speed needed to escape without more thrust. Unit: m/s.
Mass of the planet, moon, or star. Unit: kg.
Distance from the center of the body at launch. Unit: m.
Formula method and unit assumptions
Formula and example
Worked example
Estimate escape speed from a planet with known mass and radius
- 1Enter the body mass and radius.
- 2Apply ve = sqrt(2GM/r).
- 3Review the result in m/s or km/s as a baseline, not a full launch requirement.
Escape velocity is an energy threshold idea; actual launch design still depends on propulsion, drag, and flight path.
Assumptions
Common mistakes
Related formula checks
Equation context and next checks
Formula and variable setup for Escape Velocity Calculator
Calculate escape velocity for a planet, moon, or star. The page is designed to help you move from the known values to the correct formula without rebuilding the derivation every time.
For escape velocity calculator, the safest workflow is to confirm the unit system first, then map each symbol to the physical quantity in your problem statement before solving.
- ve: Escape velocity (m/s) - Minimum ideal launch speed needed to escape without more thrust.
- M: Body mass (kg) - Mass of the planet, moon, or star.
- r: Radius from center (m) - Distance from the center of the body at launch.
How to read the result
The answer estimates the threshold speed needed to avoid falling back in the ideal no-loss model.
This tool is especially useful for planetary comparison, spaceflight intuition, and gravity-energy baselines. The output becomes more trustworthy when you compare nearby cases instead of relying on one single run.
- Escape speed in m/s and km/s
- Mass and radius input
- Ideal no-atmosphere estimate
Assumptions and limits
The calculator applies the standard textbook relation for this topic, which makes it a strong first-pass answer but not always a full real-world model.
Before you use the result in a lab, design review, or report, check whether the simplified assumptions still match the physical system you care about.
- Atmospheric drag and planetary rotation are ignored.
- The launch is treated as an energy problem in the ideal gravitational field.
- The result is the ideal threshold speed, not a full mission delta-v budget.
Quick glossary
Minimum ideal launch speed needed to escape without more thrust.
Mass of the planet, moon, or star.
Distance from the center of the body at launch.
A simplified physics model that omits secondary effects so the first-order relationship is easier to inspect.
Formula checks before using the result
Formula questions
Checks before using the result
When should I use the escape velocity calculator?
Use escape velocity calculator for planetary comparison, spaceflight intuition, and gravity-energy baselines, especially when the governing formula is already known and the main need is a fast, transparent calculation.
What is the main thing the escape velocity calculator tells me?
The answer estimates the threshold speed needed to avoid falling back in the ideal no-loss model.
What can make the escape velocity calculator answer inaccurate?
The answer is exact for the formula and assumptions on the page, but it can drift when the real system violates those assumptions. Common limits include Atmospheric drag and planetary rotation are ignored. The launch is treated as an energy problem in the ideal gravitational field. The result is the ideal threshold speed, not a full mission delta-v budget.
Formula references and related examples
Formula Basis