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Orbital period calculator

Compute how long an object takes to orbit a body from the orbit radius and mass.

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Enter Orbit radius (km), Central mass (×10²⁴ kg) and the Orbital period calculator works out Period (minutes), Period (hours) straight away. For instance, with Orbit radius (km) = 6,771 and Central mass (×10²⁴ kg) = 5.972 it returns Period (minutes) = 92.418 and Period (hours) = 1.54.

How to use it

  1. Enter your values: Orbit radius (km), Central mass (×10²⁴ kg).
  2. Read the result instantly: Period (minutes), Period (hours).

Frequently asked questions

How does the Orbital period calculator work?

It takes Orbit radius (km) and Central mass (×10²⁴ kg) and derives Period (minutes) and Period (hours) from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

2 values: Orbit radius (km) and Central mass (×10²⁴ kg). Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Orbit radius (km) = 6,771 and Central mass (×10²⁴ kg) = 5.972, the calculator returns Period (minutes) = 92.418 and Period (hours) = 1.54. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

How much does the result change with different inputs?

It moves a lot. Using Orbit radius (km) = 7,448 and Central mass (×10²⁴ kg) = 11.944 instead, Period (minutes) goes from 92.418 to 75.391 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Orbit radius (km) = 6,094 and Central mass (×10²⁴ kg) = 2.986, Period (minutes) comes out at 111.595. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Checking a homework answer, sizing something before building it, and getting an order of magnitude before committing to a design — a torque on a bolt, the force a spring returns, the frequency a circuit resonates at, how long light takes to arrive.

What is the most common mistake?

Feeding in a value in the wrong unit. Physics formulas assume SI throughout, so grams instead of kilograms or centimetres instead of metres shifts the answer by powers of ten without any warning.

What is the difference between the Orbital period calculator and the Orbital velocity calculator?

This one returns Period (minutes) and Period (hours); the Orbital velocity calculator returns Orbital velocity (km/s). That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Frequency & period calculator is the closest one after this: Convert a frequency into its period (T = 1 / f) in seconds and milliseconds.

What else is worth having open alongside it?

Pendulum period calculator and Centripetal force calculator — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
ExplainerHow the Doppler Effect Works: The Formula, the Sign Convention, and Why Moving the Source Is Not the Same as Moving the ListenerFor sound, f' = f(v + v_o)/(v − v_s) — and getting the signs backwards is the classic error. Here is the convention spelled out, a 440 Hz source computed at four speeds, and why light needs a different equation entirely.ExplainerWhat Is the Reynolds Number? The Formula, the Units That Cancel, and Why 2 300 Is Only for PipesRe = ρvL/μ compares inertia with viscosity, and the units really do cancel. See the number worked out for honey, a household pipe, an artery, a swimmer and a wing — and why the 2 300 threshold belongs to pipe flow alone.ExplainerHooke's Law Explained: F = kx, Real Spring Constants, and Where It Stops HoldingHooke's law says force is proportional to stretch — but only below the elastic limit. Here is F = kx with worked numbers, what a 200 N/m spring actually feels like, and how springs combine.ExplainerHow Buoyancy Works: Archimedes' Principle, and Why Ice Floats With 10.5 % Above WaterThe upward force equals the weight of the fluid pushed aside. That one sentence decides whether something floats, and if it floats, exactly how much of it stays under.GuideThe Four Kinematics Equations: Which One to Use, and What Each One Leaves OutFive variables, four equations, and each equation is missing exactly one of them. Choose by looking at the variable the question never mentions.ExplainerProjectile Motion Explained: Range, Height, Flight Time — and Why 45° Is Not Always BestThree formulas cover the whole of projectile motion on level ground. The catch is level ground: the moment launch and landing heights differ, the 45° result stops being true.
Orbital period calculator — OneKitly