Pressure Converter

Pressure Conversion [?]
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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.

Enter the value you want to convert in the upper input box.
Select the corresponding units from the upper shortcut buttons or pull down options.
Select the units to convert to, from the lower shortcut buttons or pull down options.
The conversion will show in the lower answer box.

You can also copy and paste values into this converter, after pasting a value, click or touch the input box 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.

Tyre pressure conversion for cars, trucks, cycles, motorbikes or aircraft
Barometric conversion for mbar, hPa, psi, inHg, mmHg & Torr
Vacuum conversion for % vac, mbar, hPa, psi, inHg, mmHg & Torr
Altitude to pressure conversion from feet or metres to mbar, psi, mmHg & inHg
I/P & P/I conversion for current and pneumatic signal control instrumentation
E/P & P/E conversion for voltage and pneumatic signal control instrumentation

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 an internationally agreed definition for the conversion factor, some have an exact value with very few digits, while others have a lot of digits and may vary very slightly between reference sources, depending on the level of precision used when calculating the values.

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

Pascal SI Metric Prefix Pressure Units

These pressure units belong to the SI measurement system where the pascal is derived from the SI units by the following formulas: 1 kg·m^-1·s^-2 ⇒ 1 N·m^-2 ⇒ 1 Pa.

quectopascal (qPa) – 1 x 10^-30 Pa
rontopascal (rPa) – 1 x 10^-27 Pa
yoctopascal (yPa) – 1 x 10^-24 Pa
zeptopascal (zPa) – 1 x 10^-21 Pa
attopascal (aPa) – 1 x 10^-18 Pa
femtopascal (fPa) – 1 x 10^-15 Pa
picopascal (pPa) – 1 x 10^-12 Pa
nanopascal (nPa) – 1 x 10^-9 Pa
micropascal (µPa) – 0.000001 Pa
millipascal (mPa) – 0.001 Pa
centipascal (cPa) – 0.01 Pa
decipascal (dPa) – 0.1 Pa
pascal (Pa) – 1 Pa
decapascal (daPa) – 10 Pa
hectopascal (hPa) – 100 Pa
kilopascal (kPa) – 1,000 Pa
megapascal (MPa) – 1,000,000 Pa
gigapascal (GPa) – 1 x 10⁺⁹ Pa
terapascal (TPa) – 1 x 10⁺¹² Pa
petapascal (PPa) – 1 x 10⁺¹⁵ Pa
exapascal (EPa) – 1 x 10⁺¹⁸ Pa
zettapascal (ZPa) – 1 x 10⁺²¹ Pa
yottapascal (YPa) – 1 x 10⁺²⁴ Pa
ronnapascal (RPa) – 1 x 10⁺²⁷ Pa
quettapascal (QPa) – 1 x 10⁺³⁰ Pa

Bar Metric Prefix Pressure Units

These pressure units which belong to the metric unit system where the bar is defined as being exactly equal to 100,000 pascals.

quectobar (qbar) – 1 x 10^-25 Pa
rontobar (rbar) – 1 x 10^-22 Pa
yoctobar (ybar) – 1 x 10^-19 Pa
zeptobar (zbar) – 1 x 10^-16 Pa
attobar (abar) – 1 x 10^-13 Pa
femtobar (fbar) – 1 x 10^-10 Pa
picobar (pbar) – 1 x 10^-7 Pa
nanobar (nbar) – 1 x 10^-4 Pa
microbar (µbar) – 0.1 Pa
millibar (mbar) – 100 Pa
centibar (cbar) – 1,000 Pa
decibar (dbar) – 10,000 Pa
bar (bar) – 100,000 Pa
decabar (dabar) – 1,000,000 Pa
hectobar (hbar) – 10,000,000 Pa
kilobar (kbar) – 1 x 10⁺⁸ Pa
megabar (Mbar) – 1 x 10⁺¹¹ Pa
gigabar (Gbar) – 1 x 10⁺¹⁴ Pa
terabar (Tbar) – 1 x 10⁺¹⁷ Pa
petabar (Pbar) – 1 x 10⁺²⁰ Pa
exabar (Ebar) – 1 x 10⁺²³ Pa
zettabar (Zbar) – 1 x 10⁺²⁶ Pa
yottabar (Ybar) – 1 x 10⁺²⁹ Pa
ronnabar (Rbar) – 1 x 10⁺³² Pa
quettabar (Qbar) – 1 x 10⁺³⁵ Pa

Torr Metric Prefix Pressure Units

These pressure units are defined as being exactly equal to 1/760 of one standard atmosphere (101,325 Pa), which can be easily incorporated into calculations simply as 101325/760 Pa which is approximately equal to 133.322 pascals.

quectotorr (qTorr) – 1.33322368421053 x 10^-28 Pa
rontotorr (rTorr) – 1.33322368421053 x 10^-25 Pa
yoctotorr (yTorr) – 1.33322368421053 x 10^-22 Pa
zeptotorr (zTorr) – 1.33322368421053 x 10^-19 Pa
attotorr (aTorr) – 1.33322368421053 x 10^-16 Pa
femtotorr (fTorr) – 1.33322368421053 x 10^-13 Pa
picotorr (pTorr) – 1.33322368421053 x 10^-10 Pa
nanotorr (nTorr) – 1.33322368421053 x 10^-7 Pa
microtorr (µTorr) – 1.33322368421053 x 10^-4 Pa
millitorr (mTorr) – 0.133322368421053 Pa
centitorr (cTorr) – 1.33322368421053 Pa
decitorr (dTorr) – 13.3322368421053 Pa
torr (Torr) – 133.322368421053… Pa
decatorr (daTorr) – 1,333.22368421053 Pa
hectotorr (hTorr) – 13,332.2368421053 Pa
kilotorr (kTorr) – 1.33322368421053 x 10⁺⁵ Pa
megatorr (MTorr) – 1.33322368421053 x 10⁺⁸ Pa
gigatorr (GTorr) – 1.33322368421053 x 10⁺¹¹ Pa
teratorr (TTorr) – 1.33322368421053 x 10⁺¹⁴ Pa
petatorr (PTorr) – 1.33322368421053 x 10⁺¹⁷ Pa
exatorr (ETorr) – 1.33322368421053 x 10⁺²⁰ Pa
zettatorr (ZTorr) – 1.33322368421053 x 10⁺²³ Pa
yottatorr (YTorr) – 1.33322368421053 x 10⁺²⁶ Pa
ronnatorr (RTorr) – 1.33322368421053 x 10⁺²⁹ Pa
quettatorr (QTorr) – 1.33322368421053 x 10⁺³² Pa

Unit Groups

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