Science
Ideal gas pressure
Calculate gas pressure from amount in moles, absolute temperature and volume using the ideal gas relationship; volume is entered in cubic metres.
Calculators / Science / Gas molecular RMS speed
Gas molecular RMS speed calculator
Estimate root-mean-square molecular speed in an ideal gas from temperature and molar mass.
On this page
RMS molecular speed516.96m/s
Calculator controls
How to calculate
Estimate root-mean-square molecular speed in an ideal gas from temperature and molar mass.
RMS molecular speed =
sqrt(3*8.31446261815324*T/(M/1000)) m/sWorked example
- Absolute temperature (K): 300
- Molar mass (g/mol): 28
- RMS molecular speed: 516.96 m/s
Assumptions and limits
This is an ideal educational model. Enter quantities in the stated SI units; it does not certify equipment safety or real operating limits. Assumes thermal equilibrium and classical ideal-gas behaviour; RMS speed differs from mean and most probable speed.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Estimate root-mean-square molecular speed in an ideal gas from temperature and molar mass. Molar mass is entered in grams per mole and converted to kilograms per mole for the SI gas constant.
When this tool is useful
Molar mass is entered in grams per mole and converted to kilograms per mole for the SI gas constant.
Understanding your inputs
| Input | Example |
|---|---|
Absolute temperature (K) T | 300 |
Molar mass (g/mol) M | 28 |
Frequently asked questions
Which assumptions matter for this result?
This is an ideal educational model. Enter quantities in the stated SI units; it does not certify equipment safety or real operating limits. Assumes thermal equilibrium and classical ideal-gas behaviour; RMS speed differs from mean and most probable speed.
How can I check the worked example?
Use the displayed example inputs in the stated formula. Keep each quantity in its labelled unit and compare the unrounded result before applying display rounding.