Vacuum engineering tools & reference data
Fast, accurate calculators for everyone who works with vacuum — convert units, find boiling points, size pumps and piping, and check leak rates. Every formula is shown; everything is free.
Calculators & converters
Vacuum Unit Converter
Convert between inHg, psi, kPa, mbar, Torr, microns and % vacuum — absolute and gauge.
Boiling Point Under Vacuum
Boiling temperature of water, ethanol, acetone and more at any vacuum level.
Pump-Down Time Calculator
Evacuation time for a chamber — or the pump size you need for a target time.
Vacuum Line Sizing & Conductance
Pipe conductance, effective pumping speed, gas velocity and minimum line diameter.
Leak Rate & Gas Flow Converter
mbar·L/s, Pa·m³/s, Torr·L/s, atm·cc/s, sccm and slm — plus leak-tightness classes.
Mean Free Path & Knudsen Number
Mean free path of air, N₂, He, Ar and more, and the flow regime in your pipe.
Quick reference
| 1 bar | 14.5038 psi = 100 kPa = 750.06 Torr |
|---|---|
| 1 psi | 0.0689476 bar = 6.89476 kPa |
| Full vacuum (sea level) | 29.92 inHg vac = 0 psia = −101.325 kPa g |
| 500 microns | 66.7 Pa = 0.5 Torr = 0.667 mbar |
| 1 Torr | 133.32 Pa = 1.333 mbar = 1,000 microns |
| 25 inHg vacuum | 16.7 kPa abs · water boils at 56 °C |
| 1 mbar·L/s | 0.1 Pa·m³/s = 0.75 Torr·L/s ≈ 59.2 sccm |
Reference & guides
Pressure Units Explained
Pa, hPa, kPa, MPa, mbar, bar, atm, Torr, mmHg, microns, psi and inHg with exact values and a full conversion table.
Vacuum Levels & Ranges
Rough, medium, high and ultra-high vacuum explained with pressure ranges and applications.
Vacuum Pump Types
Rotary vane, scroll, screw, Roots, liquid ring, turbo, diffusion, cryo and ion pumps compared.
How Vacuum Pumps Work
Animated step-by-step guides: rotary vane, turbomolecular, liquid ring and vacuum ejector.
Vacuum Applications
HVAC evacuation, vacuum distillation, freeze drying, vacuum furnaces, VPI and vacuum sewers.
Busch Parts Lists & Catalogue
Independent guide: where to find Busch vacuum pump parts lists and catalogue data, with two free PDFs.
Vacuum Pump Brands
The main global vacuum pump manufacturers, who owns whom, and which technologies each one makes.
Vacuum Glossary
Key vacuum terms explained briefly: ultimate pressure, pumping speed, conductance, leak rate, outgassing and more.
Vacuum Gauges
Bourdon, capacitance, Pirani, thermocouple and ionization gauges — ranges and accuracy.
Water Vapor Pressure Table
Vapor pressure of water from −40 °C to 150 °C in Pa, mbar, Torr, psi and inHg.
Vacuum Training & Careers
University schools, short courses, leak testing certification and career paths in the vacuum industry.
Vacuum Pump Service Directory (US)
Find manufacturer service centers and independent shops for vacuum pump service, repair and maintenance in the US.