Density of Helium (He) at STP
Helium (He, molar mass 4 g/mol) has a density of approximately 0.179 g/L at STP, making it the second lightest gas.
How to use this tool
- Enter molar mass in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your density at stp (0 °c, 100 kpa) and the full breakdown beneath it.
Helium is one of the lightest gases, with a density of only about 0.179 g/L at STP.
Frequently asked questions
- What is STP?
- Standard Temperature and Pressure. IUPAC redefined it in 1982/2010 as 0 °C (273.15 K) and 100 kPa. Older texts used 101.325 kPa (1 atm), giving V_m = 22.414 L/mol. This calculator uses the current IUPAC definition.
- Is this formula exact?
- Only for ideal gases. Real gases deviate, especially at high pressures or near their boiling points. For most gases at STP the deviation is < 0.1%.