RMS Speed Calculator (Gas)

Calculate the Root Mean Square (RMS) speed of gas molecules.

Gas Properties

Temperature

Gas Type

Molar Mass (M) (kg/mol)

Note: Use kg/mol (e.g., O2 is 0.032 kg/mol)

RMS Speed

Enter temperature and gas type

About this calculator

Quick Reference

R8.314 J/mol·K

TTemperature (K)

MMolar Mass (kg/mol)

Overview

RMS speed is a measure of the speed of particles in a gas, defined as the square root of the average velocity-squared of the molecules.

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Pro Tips

v_rms = √(3RT/M)
Lighter gases (like H2) have much higher RMS speeds than Heavier gases (like CO2) at the same temperature.
Temperature must be in Kelvin for calculation (calculator handles conversion).

Fun Facts

"At room temperature, air molecules move at about 500 m/s (roughly the speed of a bullet)."
"RMS speed determines the speed of sound in a gas."

Formula: v = √(3RT/M)