Pressure & Vacuum Converter

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Instant automatic conversion for all pressure units 🚀

🌐 Common Units

⚙️ Engineering & Fluid Units

📝 Conversion Formulas & Steps

This tool uses Pascal (Pa) as the standard SI unit for baseline conversion. Key conversion values:

  • 1 Pa = 1 N/m2
  • 1 atm = 101,325 Pa
  • 1 Torr ≈ 133.322 Pa
  • 1 mTorr = 10-3 Torr
  • 1 bar = 100,000 Pa
  • 1 mbar = 100 Pa
  • 1 psi ≈ 6,894.76 Pa

Usage Steps:

  1. Enter a value in any input field.
  2. All other units will update automatically.
  3. Select and copy any result value.

🔬 Application Areas

Pa / kPa / MPa

🏗️ Materials / Struct / Food

SI standard. kPa for weather; MPa for material strength.

bar / mbar

⛽ Industry / Diving / Meteo

European industry & meteorology. 1 hPa = 1 mbar.

atm

🧪 Chemistry / Diving

Standard atmospheric pressure at sea level.

Torr / mTorr

⚛️ Vacuum / Semi

Core for vacuum tech & semiconductors.

psi

🚗 Tires / Fire Sys

Imperial unit, common for tires and fire systems.

kgf/cm²

🏭 Industry / Hydraulic

Traditional industry & hydraulic equipment.

mmH₂O

🌬️ HVAC / Cleanroom

For tiny pressure diffs like cleanrooms & HVAC.

inHg

✈️ Aviation / Meteo

US aviation altimeters & weather reports.

How To Choose The Right Pressure Unit

Pressure conversions are easy to calculate but easy to misread in practice because industries often reuse similar-looking units for very different operating ranges. Atmospheric work, cleanroom differentials, rough vacuum, and high-pressure mechanical systems all tend to speak different unit languages.

  • Use Pa, kPa, and MPa when you want a direct SI workflow.
  • Use mbar or hPa when reading weather and many European process references.
  • Use Torr or mTorr when reviewing vacuum equipment or chamber conditions.
  • Use psi when the source is a tire, compressor, regulator, or US equipment sheet.

If a result looks unfamiliar, compare its order of magnitude to a known reference such as 1 atm = 101.325 kPa before copying it into a report.

Frequently Asked Questions

Why do small rounding differences appear between tables?

Different handbooks round conversion constants differently. For most practical work that is normal, but regulated documentation should follow the exact constants required by your SOP or vendor standard.

Is psi the same as psig?

No. This converter handles unit conversion, not gauge-versus-absolute context. Always confirm whether your source measurement is absolute pressure or gauge pressure before using the result.

When should I prefer mTorr or mmH2O?

mTorr is common in vacuum systems, while mmH2O is more useful for tiny pressure differences in airflow, cleanroom, and duct measurements.