Orbital Velocity Calculator

Calculate the speed required for a circular orbit at a given altitude.

About Orbital Velocity Calculator

Orbital velocity falls as altitude rises, so higher orbits are slower and take longer. Low Earth orbit requires about 7.7 km/s and completes roughly sixteen orbits a day. Because higher orbits are slower, a satellite cannot simply speed up to catch another in the same orbit — it must change altitude, which is the core counter-intuition of orbital mechanics.

Formula

Orbital Velocity

v = √(G M ÷ r), with r measured from the centre of the body

r: Orbital radius, altitude plus the body radius

Worked example

With the default values below, Orbital Velocity Calculator returns Orbital Velocity of 7,672.32. Change any input above and every figure here is recalculated in your browser.

Inputs used

Mass of the central bodyminimum 1 kg: 5,972,000,000,000,000,000,000,000 kg
Radius of the central bodyminimum 1 m: 6,371,000 m
Orbital altitudeminimum 0 m: 400,000 m

Results

Orbital Velocity: 7,672.32 m/s
Orbital Velocity: 7.6723 km/s
Orbital Period: 92.42 min
Orbital Radius From the Centre: 6,771,000 m
Orbits per Day: 15.581

Step by step

1Values used
2Orbital Velocity
3Orbital Velocity= 7,672.32 m/s
4Orbital Velocity= 7.6723 km/s
5Orbital Period= 92.42 min
6Orbital Radius From the Centre= 6,771,000 m
7Orbits per Day= 15.581

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Orbital Velocity calculated?

v = √(G M ÷ r), with r measured from the centre of the body Orbital velocity falls as altitude rises, so higher orbits are slower and take longer. Low Earth orbit requires about 7.7 km/s and completes roughly sixteen orbits a day.

Why does Orbital Velocity matter?

Because higher orbits are slower, a satellite cannot simply speed up to catch another in the same orbit — it must change altitude, which is the core counter-intuition of orbital mechanics.

What values do I need to enter?

This calculator takes 3 inputs: Mass of the central body, Radius of the central body, Orbital altitude. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.