Standard Temperature and Pressure Calculator
Calculate STP Conditions
About Standard Temperature and Pressure
Standard Temperature and Pressure (STP) are reference conditions used in chemistry and physics for comparing gas properties. Different organizations use slightly different definitions.
IUPAC Definition:
Temperature: 0°C (273.15 K)
Pressure: 100 kPa (0.987 atm)
NIST Definition:
Temperature: 20°C (293.15 K)
Pressure: 101.325 kPa (1 atm)
Traditional Definition:
Temperature: 0°C (273.15 K)
Pressure: 1 atm (101.325 kPa)
Ideal Gas Law at STP:
PV = nRT
Molar Volume (Ideal Gas):
V_m = RT/P
Gas Density:
ρ = PM/RT
Where:
- P = Pressure
- V = Volume
- n = Number of moles
- R = Gas constant (8.314 J/(mol·K))
- T = Temperature (K)
- M = Molar mass
STP conditions are essential for gas calculations, stoichiometry, and comparing gas properties across different conditions.