Pressure Converter & Conversion Guide

Pressure Conversion [?]
From
Select pressure unit bar psi kg/cm² mbar kPa Pa Pa hPa kPa MPa N/m² N/mm² bar mbar mmH₂O 4°C cmH₂O 4°C dmH₂O 4°C mH₂O 4°C inH₂O 4°C ftH₂O 4°C mmHg 0°C cmHg 0°C inHg 0°C g/cm² kg/cm² dyn/cm² oz/in² psi ksi tsi uk long tsi us short tsf us short psf atm at Torr mTorr bar centimetres of mercury at 0°C centimetres of water at 4°C decimetres of water at 4°C dynes per sq centimetre feet of water at 4°C grams per sq centimetre hectopascals inches of mercury at 0°C inches of water at 4°C kilograms per sq centimetre kilopascals kilopounds per sq inch megapascals metres of water at 4°C microns of mercury at 0°C millibars millimetres of mercury at 0°C millimetres of water at 4°C millitorrs newtons per sq metre newtons per sq millimetre ounces per sq inch pascals pounds per sq foot pounds per sq inch standard atmospheres technical atmospheres tons per sq foot (us short) tons per sq inch (uk long) tons per sq inch (us short) torrs
To
Select pressure unit bar psi kg/cm² mbar kPa Pa Pa hPa kPa MPa N/m² N/mm² bar mbar mmH₂O 4°C cmH₂O 4°C dmH₂O 4°C mH₂O 4°C inH₂O 4°C ftH₂O 4°C mmHg 0°C cmHg 0°C inHg 0°C g/cm² kg/cm² dyn/cm² oz/in² psi ksi tsi uk long tsi us short tsf us short psf atm at Torr mTorr bar centimetres of mercury at 0°C centimetres of water at 4°C decimetres of water at 4°C dynes per sq centimetre feet of water at 4°C grams per sq centimetre hectopascals inches of mercury at 0°C inches of water at 4°C kilograms per sq centimetre kilopascals kilopounds per sq inch megapascals metres of water at 4°C microns of mercury at 0°C millibar millimetres of mercury at 0°C millimetres of water at 4°C millitorrs newtons per sq metre newtons per sq millimetre ounces per sq inch pascals pounds per sq foot pounds per sq inch standard atmospheres technical atmospheres tons per sq foot (us short) tons per sq inch (uk long) tons per sq inch (us short) torrs

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User Guide

This converter and dynamic conversion scale will calculate the equivalent pressure value from one pressure measurement unit to another and generate a conversion table based on the selected units.

1. Enter the value you want to convert in the upper input box.
2. Select the corresponding units from the upper pull down options.
3. Select the units to convert to, from the lower pull down options.
4. The conversion will show in the lower text box.

You can use this converter to copy and paste values as well, after pasting a value, just click/touch one of the text boxes or select a unit to convert the value.

Conversion Guide

Convert pressure units with the pressure unit converting tool, look up a conversion from the tables, identify a pressure unit and its group association with other pressure units, or find the relevant pressure conversion factor in pascals.

Conversion Tables

Choose a look up table for a specific pressure conversion application.

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Conversion Factors

The following list shows each pressure unit and its equivalent value converted into pascals (Pa). The pascal is the SI unit for measuring pressure.

Unique Conversion Factors

These units have a defined conversion value which is internationally agreed and are always the same value

Symbol	Name	Pascals Value
bar	Bar	100,000
psi, pfsi, lb/in², lbf/in²	Pounds Force Per Square Inch	6894.75729316836…
mbar, mb, mbr	Millibar	100
N/m²	Newton Per Square Metre	1
Pa	Pascal	1
hPa	Hectopascal	100
kPa	Kilopascal	1,000
MPa	Megapascal	1,000,000
kg/cm², kgf/cm²	Kilogram Per Square Centimetre	98,066.5
Torr	Torr	133.322368421053…
mTorr	Millitorr	0.133322368421053…
atm	Standard Atmosphere	101,325
at	Technical Atmosphere	98,066.5
dyn/cm², dyne/cm²	Dyne Per Square Centimetre	0.1
oz/in², ozf/in²	Ounce Per Square Inch	430.922330823023…
tsi, tfsi (uk, long)	Ton Per Square Inch (uk, long)	15,444,256.3366971…
tsi, tfsi (usa, short)	Ton Per Square Inch (usa, short)	13,789,514.5863367…
tsf, tfsf (usa, short)	Ton Per Square Foot (usa, short)	95,760.5179606717…
psf, pfsf	Pounds Force Per Square Foot	47.8802589803358…
g/cm², gf/cm²	Gram Per Square Centimetre	98.0665

N.B. Numbers which include […] on the end are rounded.

Manometric Conversion Factors

The following units are known as manometric pressure units and are derived from the pressure exerted by a column of liquid under the acceleration of earth’s gravity. Each manometric pressure unit is shown with its equivalent value converted into pascals (Pa). The pascal is the SI unit for measuring pressure.

Since the pressure of the fluid column can vary with changes in liquid density and local gravity it is important to quantify these factors when using these units. The physical assumptions that these conversions factors are based can be found at the bottom of this section.

The use of manometric units is discouraged by national standard organisations because they do not precisely represent the true pressure and there are differing conventions used for the temperature and density of the liquid which can lead to variation in accuracy.

Symbol	Name	Pascals Value
mmH2O, mmWG, mmWC	Millimetres of Water	9.80665
cmH2O, cmWG, cmWC	Centimetres of Water	98.0665
mH2O, mWG, mWC	Metres of Water	9,806.65
inH2O, inWG, inWC	Inches of Water	249.08891
ftH2O, ftWG, ftWC	Feet of Water	2,989.06692
mmHg	Millimetres of Mercury	133.322387415
cmHg	Centimetres of Mercury	1,333.22387415
inHg	Inches of Mercury	3,386.388640341
µHg, µmHg	Microns of Mercury	0.133322387415

The above manometric pressure units assume the following in their derivation and although they are not physical constants they have been accepted as popular conventions and are used universally:

• Standard acceleration due to gravity of 9.80665 m/s²
• Density of pure water at 4 deg C is 1000 kg/m³
• Density of mercury at 0 deg C is 13,595.1 kg/m³

Unit Groups

Many units have a similar application or derivation, the use of each varies depending on country, industry and pressure value

Units derived from ‘pascal’ the SI unit for pressure

• Pa, hPa, kPa, MPa, N/m²
• bar, mbar, mb, mbr
• dyn/cm², dyne/cm², dynes/cm², d/cm²

Force related pressure units

• kg/cm², kgf/cm², at, g/cm², gf/cm²
• psi, pfsi, lb/in², lbf/in², oz/in², ozf/in²
• tsi (uk, long), tfsi (uk, long), tsi (usa, short), tfsi (usa, short), tsf (usa, short), tfsf (usa, short), psf, pfsf

Water related pressure units

• mm H2O, cm H2O, m H2O
• mm WG, cm WG, m WG
• mm WC, cm WC, m WC
• in H2O, ft H2O
• in WG, ft WG
• in WC, ft WC

Mercury related pressure units

• mm Hg, cm Hg,
• in Hg
• µ Hg, µm Hg, micron Hg

Pressure units derived from 1 standard atmosphere (1 atm = 101325 pascals)

• atm, Torr, mTorr