Pressure Converter
Convert between pressure units and see how they compare. Gauge readings are relative to the atmosphere; absolute readings are relative to a vacuum. Exact factors, a quick reference table and worked examples.
101.325 kPa = 1 atm
The same value in every unit
| Unit | Symbol | Value |
|---|---|---|
| Pascal | Pa | 101 325 |
| Kilopascal | kPa | 101.325 |
| Megapascal | MPa | 0.101325 |
| Bar | bar | 1.01325 |
| Millibar | mbar | 1 013.25 |
| Pound per square inch | psi | 14.69595 |
| Atmosphere | atm | 1 |
| Millimeter of mercury | mmHg | 759.9999 |
| Inch of mercury | inHg | 29.92126 |
| Millimeter of water | mmH₂O | 10 332.27 |
| Kilogram-force per cm² | kgf/cm² | 1.033227 |
How to convert pressure units
Every pressure unit is related to one base unit (Pascal, Pa) by an exact factor. To convert, multiply by the factor of the unit you start from and divide by the factor of the unit you want.
value in new unit = value × (factor of old unit ÷ factor of new unit)
For example, 1 kPa = 1 000 Pa and 1 atm = 101 325 Pa, so 1 kPa = 0.009869233 atm.
Quick reference table
How many of the units in the column headings make up one of the unit in each row.
| One… | = Pa | = kPa | = MPa | = bar | = mbar | = psi |
|---|---|---|---|---|---|---|
| 1 Pa | 1 | 0.001 | 1 × 10⁻⁶ | 1 × 10⁻⁵ | 0.01 | 0.0001450377 |
| 1 kPa | 1 000 | 1 | 0.001 | 0.01 | 10 | 0.1450377 |
| 1 MPa | 1 000 000 | 1 000 | 1 | 10 | 10 000 | 145.0377 |
| 1 bar | 100 000 | 100 | 0.1 | 1 | 1 000 | 14.50377 |
| 1 mbar | 100 | 0.1 | 0.0001 | 0.001 | 1 | 0.01450377 |
| 1 psi | 6 894.757 | 6.894757 | 0.006894757 | 0.06894757 | 68.94757 | 1 |
| 1 atm | 101 325 | 101.325 | 0.101325 | 1.01325 | 1 013.25 | 14.69595 |
| 1 mmHg | 133.3224 | 0.1333224 | 0.0001333224 | 0.001333224 | 1.333224 | 0.01933678 |
| 1 inHg | 3 386.389 | 3.386389 | 0.003386389 | 0.03386389 | 33.86389 | 0.4911541 |
| 1 mmH₂O | 9.80665 | 0.00980665 | 9.80665 × 10⁻⁶ | 9.80665 × 10⁻⁵ | 0.0980665 | 0.001422334 |
| 1 kgf/cm² | 98 066.5 | 98.0665 | 0.0980665 | 0.980665 | 980.665 | 14.22334 |
Common values: kPa to atm
| Kilopascal (kPa) | Atmosphere (atm) |
|---|---|
| 1 kPa | 0.009869233 atm |
| 2 kPa | 0.01973847 atm |
| 5 kPa | 0.04934616 atm |
| 10 kPa | 0.09869233 atm |
| 20 kPa | 0.1973847 atm |
| 50 kPa | 0.4934616 atm |
| 100 kPa | 0.9869233 atm |
| 200 kPa | 1.973847 atm |
| 500 kPa | 4.934616 atm |
| 1 000 kPa | 9.869233 atm |
Worked examples
Convert 101.325 kPa to atm
- 1 kPa = 1 000 Pa and 1 atm = 101 325 Pa.
- 101.325 × 1 000 ÷ 101 325 = 1 atm.
Convert 50 MPa to Pa
- 1 MPa = 1 000 000 Pa and 1 Pa = 1 Pa.
- 50 × 1 000 000 ÷ 1 = 50 000 000 Pa.
Convert 250 kgf/cm² to kPa
- 1 kgf/cm² = 98 066.5 Pa and 1 kPa = 1 000 Pa.
- 250 × 98 066.5 ÷ 1 000 = 24 516.63 kPa.
The units explained
| Unit | Symbol | Exact factor | Where it is used |
|---|---|---|---|
| Pascal | Pa | 1 Pa = 1 Pa | SI unit; acoustics and low pressures |
| Kilopascal | kPa | 1 kPa = 1 000 Pa | Engineering, HVAC |
| Megapascal | MPa | 1 MPa = 1 000 000 Pa | Materials, hydraulics, structures |
| Bar | bar | 1 bar = 100 000 Pa | Industry, hydraulics, pneumatics |
| Millibar | mbar | 1 mbar = 100 Pa | Weather, vacuum |
| Pound per square inch | psi | 1 psi = 6 894.757 Pa | US customary, tires, compressed air |
| Atmosphere | atm | 1 atm = 101 325 Pa | General, atmospheric |
| Millimeter of mercury | mmHg | 1 mmHg = 133.3224 Pa | Vacuum, blood pressure |
| Inch of mercury | inHg | 1 inHg = 3 386.389 Pa | Weather, aviation (US) |
| Millimeter of water | mmH₂O | 1 mmH₂O = 9.80665 Pa | HVAC duct and filter pressure |
| Kilogram-force per cm² | kgf/cm² | 1 kgf/cm² = 98 066.5 Pa | Older gauges (technical atmosphere) |
Key facts
- Absolute pressure = gauge pressure + atmospheric pressure (about 101.325 kPa at sea level).
- 1 bar = 100 kPa = 14.504 psi. 1 atm = 101.325 kPa = 1.01325 bar.
- P = F ÷ A: a force spread over an area. Hydrostatic pressure P = ρ g h, about 9.81 kPa per meter of water.
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FAQ
How many Atmosphere units are in one Kilopascal?
1 kPa = 0.009869233 atm.
How do I convert kPa to atm?
Multiply by 0.009869233 (the factor 1 000 ÷ 101 325). To go back, divide by 0.009869233 or multiply by 101.325.
What is the pascal (Pa) used for?
SI unit; acoustics and low pressures.
What is the kilopascal (kPa) used for?
Engineering, HVAC.
Are the conversion factors exact?
Where a unit is defined exactly (the inch is 25.4 mm, the pound is 0.45359237 kg, standard gravity is 9.80665 m/s²) the factor is exact; others are given to ten or more digits. Results are shown to seven significant digits.
References
- NIST Special Publication 811, Guide for the Use of the International System of Units (SI), and NIST Handbook 44, Appendix C (general tables of units of measurement).
- BIPM, The International System of Units (SI Brochure), 9th edition; ISO 80000 (quantities and units).
Last reviewed: November 2026.