Convert Standard Atmospheres to Millipascals
Convert Standard Atmospheres (atm) to Millipascals (mPa) instantly and accurately.
Conversion Formula
mPa = atm × 101325000
About Standard Atmospheres
The standard atmosphere (atm) = exactly 101,325 Pa - defined by the 10th CGPM (1954) as the reference air pressure at sea level. Used to define STP (0°C and 1 atm) for gas law and thermochemistry. Chemical equilibrium constants (Kp), Henry's law solubility, and thermodynamic tables are tabulated at 1 atm. ISA aviation standard: sea-level 1 atm / 15°C, pressure halving every ~5.5 km. Diving physics: +1 atm per 10 m depth (fresh water) so 30 m = 4 atm absolute. Diamond formation in Earth's mantle: ~50,000 atm. 1 atm = 101,325 Pa.
About Millipascals
A millipascal (mPa) is 10⁻³ Pa. It appears primarily in rheology as the millipascal-second (mPa·s = centipoise) for dynamic viscosity: water at 20°C is 1.002 mPa·s; olive oil ~80 mPa·s; honey 2,000-10,000 mPa·s. Food technology, polymer processing, pharmaceutical formulation, and inkjet printing all specify flow behaviour in mPa·s. Partial pressures of trace atmospheric gases and ultra-high-vacuum leak rates measured by residual gas analysers are also expressed in millipascals. 1 mPa = 10⁻³ Pa.
Quick Reference Table
| Standard Atmospheres (atm) | Millipascals (mPa) |
|---|---|
| 1 atm | 101325000 mPa |
| 2 atm | 202650000 mPa |
| 5 atm | 506625000 mPa |
| 10 atm | 1.013 × 109 mPa |
| 25 atm | 2.533 × 109 mPa |
| 50 atm | 5.066 × 109 mPa |
| 100 atm | 1.013 × 1010 mPa |