Pressure Converters
Convert between pressure units: atm, Pa, kPa, mmHg, torr, psi, and bar. Used in gas law problems, vacuum systems, and chemical engineering.
Pressure units vary widely across chemistry sub-disciplines. Gas law textbook problems typically use atmospheres (atm), the SI system uses pascals (Pa), barometers read in mmHg (torr), and industrial equipment often reports in psi or bar. Accurate conversion between these units is critical for getting correct results in PV = nRT calculations and understanding reaction conditions.
70 Pressure Conversions
Atmospheres to Bar Converter
bar = atm × 1.01325
Convert atmospheres to bar by multiplying by 1.01325. The direction that matters most when you're moving older atm-referenced thermodynamic data into a modern bar-standard framework.
Atmospheres to Inches of Mercury Converter
inHg = atm × 29.9213
Convert atmospheres to inches of mercury by multiplying by 29.9213. Useful any time standard chemistry pressure and the inHg unit US barometric and HVAC reports use have to agree.
Atmospheres to Kilopascals Converter
kPa = atm × 101.325
1 atm equals exactly 101.325 kPa. That's the conversion you do before any pressure goes into an equation written in SI-consistent units — gas constant in J/(mol·K), volume in liters, and so on.
Atmospheres to Millibar Converter
mbar = atm × 1013.25
Convert atmospheres to millibar by multiplying by 1013.25. Used at the handoff between textbook atm values and the mbar unit vacuum gauges and meteorological reports use.
Atmospheres to mmHg (Torr) Converter
mmHg = atm × 760
Convert atmospheres to mmHg using the exact factor 1 atm = 760 mmHg. The unit that comes up every time a vapor pressure or manometer reading meets a gas-law calculation.
Atmospheres to Pascals Converter
Pa = atm × 101325
Convert atmospheres to pascals by multiplying by 101,325. The exact step from the textbook atm unit into the SI base pressure that physical-chemistry equations expect.
Atmospheres to PSI Converter
psi = atm × 14.696
Convert atmospheres to pounds per square inch by multiplying by 14.696. Useful any time textbook-scale pressures and the psi gauges on US compressed-gas regulators and HPLC pumps have to agree.
Atmospheres to Torr Converter
torr = atm × 760
Convert atmospheres to torr by multiplying by 760. The standard step between textbook-scale pressures and the torr readings that show up on a vacuum gauge.
Bar to Atmospheres Converter
atm = bar / 1.01325
Convert bar to atmospheres by dividing by 1.01325. Close enough to 1 that the numbers look almost identical, but the 1.3% gap matters in precise thermodynamic work.
Bar to Kilopascals Converter
kPa = bar × 100
Convert bar to kilopascals by multiplying by 100. The cleanest pressure conversion in chemistry — 1 bar is 100 kPa exactly, by definition.
Bar to Millibar Converter
mbar = bar × 1000
Convert bar to millibar by multiplying by 1000. The clean metric step within the bar system, useful for switching between high-pressure work and the mbar resolution most vacuum gauges show.
Bar to mmHg Converter
mmHg = bar × 750.062
Convert bar to mmHg by multiplying by 750.062. Used at the handoff between the modern bar-based standard and older mercury-column vapor-pressure data.
Bar to Pascals Converter
Pa = bar × 100000
1 bar = 100,000 Pa, exactly. Most chemistry data is written in bar; pure-SI equations expect pascals. The factor is just bookkeeping on the exponent — the only thing it really changes is how unwieldy the number gets at atmospheric scale.
Bar to PSI Converter
psi = bar × 14.50377
Convert bar to psi by multiplying by 14.50377. Used at the handoff between European-spec bar pressure ratings and US-spec gauges that read in pounds per square inch.
Bar to Torr Converter
torr = bar × 750.062
Convert bar to torr by multiplying by 750.062. Comes up at the boundary of IUPAC standard pressure and the torr unit vacuum work and vapor-pressure tables traditionally use.
Centipoise to Pascal-Seconds Viscosity Converter
Pa·s = cP × 0.001
Convert dynamic viscosity from centipoise to pascal-seconds by dividing by 1000. The clean SI step that bridges the chemistry-friendly cP unit and the Pa·s required by engineering calculations.
Centistokes to Stokes Kinematic Viscosity Converter
St = cSt ÷ 100
Convert centistokes to stokes by dividing by 100. The decimal step bridging modern lubricant grading and the CGS form older fluid-mechanics texts use.
Inches of Mercury to Atmospheres Converter
atm = inHg × 0.033421
29.92 inHg is 1 atm — the sea-level standard. The factor 0.033421 atm/inHg lives at the seam between US barometric readings and the atm-anchored arithmetic of chemistry calculations.
Inches of Mercury to Kilopascal Converter
kPa = inHg × 3.38639
Convert inches of mercury to kilopascals by multiplying by 3.38639. Comes up at the boundary of US barometric and HVAC pressure readings and the SI-derived kPa unit.
Inches of Mercury to mmHg Converter
mmHg = inHg × 25.4
Convert inches of mercury to mmHg by multiplying by 25.4. The clean step between US-spec barometric pressure readings and the mmHg unit chemistry vapor-pressure tables use.
Kilopascal to Inches of Mercury Converter
inHg = kPa × 0.295300
Convert kilopascals to inches of mercury by multiplying by 0.2953. Used at the handoff between SI-aligned process pressure data and US-spec inHg gauges and barometric reports.
Kilopascals to Atmospheres Converter
atm = kPa ÷ 101.325
Convert kilopascals to atmospheres by dividing by 101.325. The step for dropping an SI pressure reading into a gas-law equation that expects atm.
Kilopascals to Bar Converter
bar = kPa / 100
Convert kilopascals to bar by dividing by 100. The cleanest pressure conversion in chemistry, since 1 bar = 100 kPa exactly by definition.
Kilopascals to mmHg Converter
mmHg = kPa × 7.50062
Convert kilopascals to mmHg by multiplying by 7.50062. Useful any time modern SI pressure readings and older mmHg-based vapor-pressure tables have to agree.
Kilopascals to Pascals Converter
Pa = kPa × 1000
Convert kilopascals to pascals by multiplying by 1000. The base SI step that lets a kPa instrument reading meet a calculation written for the SI base pressure unit.
Kpa to Mbar Converter
mbar = kPa × 10
Multiply kPa by 10 to get mbar. Trivial decimal shift, but the routine handoff between SI process-control pressures and the mbar scale European vacuum equipment runs in.
kPa to PSI Converter
psi = kPa × 0.145038
Convert kilopascals to psi by multiplying by 0.145038. Useful any time SI-spec process pressures and the psi readings on US-built gauges and regulators have to agree.
kPa to Torr Converter
torr = kPa × 7.50062
Multiply kPa by 7.50062 to get torr. The factor comes from 760 torr = 101.325 kPa — the historical definition of one atmosphere. It bridges modern SI vapor-pressure data and torr-based legacy references.
Millibar to Atmospheres Converter
atm = mbar / 1013.25
Convert millibar to atmospheres by dividing by 1013.25. The unit you'll find on most lab vacuum gauges — converting pins the reading to the atm scale most chemistry calculations expect.
Millibar to Bar Converter
bar = mbar / 1000
Convert millibar to bar by dividing by 1000. The clean prefix step from instrument-scale vacuum readings into the bar unit IUPAC thermodynamics uses.
Millibar to kPa Converter
kPa = mbar / 10
Convert millibar to kilopascals by dividing by 10. The decimal step between mbar gauge readings and the kPa values that show up in SI-aligned thermodynamic calculations.
Millibar to mmHg Converter
mmHg = mbar × 0.750062
Convert millibar to mmHg by multiplying by 0.750062. Useful any time modern vacuum-gauge readings in mbar and the mmHg unit chemistry vapor-pressure tables and pharmacopoeias still use have to agree.
Millibar to Pascals Converter
Pa = mbar × 100
Convert millibar to pascals by multiplying by 100. The exact prefix step from vacuum-gauge readings into the SI base pressure unit.
Millibar to PSI Converter
psi = mbar × 0.014504
Convert millibar to psi by multiplying by 0.014504. Useful any time European-spec mbar instrumentation and US-spec psi gauges and regulators have to agree.
Millibar to Torr Converter
torr = mbar × 0.750062
Convert millibar to torr by multiplying by 0.750062. A unit step between modern vacuum-gauge readings in mbar and the torr units traditional vapor-pressure tables and older catalysis literature use.
mmHg to Atmospheres Converter
atm = mmHg ÷ 760
Convert mmHg to atmospheres by dividing by 760. The step you make any time a manometer or barometer reading has to drop into a gas-law calculation that wants atm.
mmHg to Bar Converter
bar = mmHg × 0.001333224
Convert mmHg to bar by multiplying by 0.001333224. The step between mercury-column readings and the bar unit that IUPAC uses for standard thermodynamic pressure.
mmHg to Inches of Mercury Converter
inHg = mmHg ÷ 25.4
Convert mmHg to inches of mercury by dividing by 25.4. Needed when lab manometer mmHg readings crosses into the inHg form legacy US vacuum gauges and barometric reports expect.
mmHg to Kilopascals Converter
kPa = mmHg × 0.13332
Convert mmHg to kilopascals by multiplying by 0.13332. A unit step between legacy vapor-pressure tables and clinical readings into SI pressure.
mmHg to Millibar Converter
mbar = mmHg × 1.33322
Convert mmHg to mbar by multiplying by 1.33322. Shows up when traditional mercury-manometer readings must feed into the SI-aligned mbar form modern instrumentation report.
mmHg to Pascals Converter
Pa = mmHg × 133.322
Convert mmHg to pascals by multiplying by 133.322. Comes up at the boundary of mercury-column readings and the SI base pressure unit physical chemistry expects.
Mmhg to Psi Converter
psi = mmHg ÷ 51.7149 (equivalently, psi = mmHg × 0.0193368)
Convert mmHg to psi by dividing by 51.7149. Used when mercury-manometer readings must meet the psi form US-built gas regulators and HPLC pump displays expect.
mmHg to Torr Converter
torr = mmHg × 1 (numerically identical)
Convert mmHg to torr — numerically identical to within 1 part in 7 million. The two units describe the same pressure scale by separate definitions.
Pa to Mbar Converter
mbar = Pa ÷ 100 (equivalently, mbar = Pa × 0.01)
Convert Pa to mbar by dividing by 100. The factor falls cleanly out of 1 mbar = 100 Pa exactly.
Pascal Seconds to Poise Converter
P = Pa·s × 10
Convert Pa·s to poise by multiplying by 10. A unit step between SI rheometer output into the CGS poise units classical fluid-dynamics references use.
Pascal to PSI Converter
psi = Pa × 0.000145038
Convert Pa to psi by multiplying by 1.45038 × 10⁻⁴. Used at the handoff between SI pressure data into the psi units US industrial equipment uses.
Pascal to Torr Converter
torr = Pa × 0.007501
Convert pascals to torr by multiplying by 0.007501, or dividing by 133.322. The step that bridges SI-aligned pressure readings with the vacuum-chemistry convention.
Pascal-Seconds to Centipoise Viscosity Converter
cP = Pa·s × 1000
1 Pa·s = 1000 cP. Pharmacopoeial specs are still written in centipoise; modern rheometers read out in pascal-seconds. The conversion is what lets the two talk.
Pascals to Atmospheres Converter
atm = Pa / 101325
Convert pascals to atmospheres by dividing by 101,325. The step that takes an SI base-unit pressure reading into the atm units gas-law textbook problems use.
Pascals to Bar Converter
bar = Pa / 100000
Convert pascals to bar by dividing by 100,000. The exact decimal step from SI base pressure into the bar unit IUPAC standard-state thermodynamics uses.
Pascals to Kilopascals Converter
kPa = Pa / 1000
Convert pascals to kilopascals by dividing by 1000. The clean prefix step that makes SI base pressure values readable for everyday chemistry calculations.
Pascals to mmHg Converter
mmHg = Pa × 0.0075006
Pa × 0.0075006 = mmHg. The conversion exists because clinical reporting, vapor-pressure tables, and vacuum specs never gave up the mercury-column unit, even after SI made the pascal the default.
Pascals to Torr Converter
torr = Pa ÷ 133.322
Convert pascals to torr by dividing by 133.322. The translation step that turns a SI-style pressure reading into the unit vacuum chemists still think in.
Poise to Pascal-Seconds Viscosity Converter
Pa·s = P × 0.1
Convert poise to pascal-seconds by multiplying by 0.1. Useful any time CGS legacy rheology data into the SI form contemporary journals require have to agree.
PSI to Atmospheres Converter
atm = psi / 14.696
Convert pounds per square inch to atmospheres by dividing by 14.696. The step you make any time a US-sourced pressure reading needs to meet a chemistry calculation in atm.
PSI to Bar Converter
bar = psi × 0.0689476
Convert pounds per square inch to bar by multiplying by 0.0689476. Useful any time a US-style gauge reading and a metric pressure spec have to agree.
PSI to Kilopascals Converter
kPa = psi × 6.89476
Convert psi to kilopascals by multiplying by 6.89476. Useful any time US-spec gauge readings and the kPa values SI-aligned chemistry calculations expect have to agree.
PSI to Millibar Converter
mbar = psi × 68.9476
1 psi works out to 68.9476 mbar. The arithmetic shows up whenever US-customary regulator pressures meet European lab equipment that displays in mbar — modern regulators tend to ship with both scales on the gauge for exactly this reason.
PSI to mmHg Converter
mmHg = psi × 51.71493
Convert psi to mmHg by multiplying by 51.7149. Used when US-customary regulator pressures must meet the mmHg form mercury manometers and clinical reports expect.
PSI to Pascal Converter
Pa = psi × 6894.76
Convert psi to pascals by multiplying by 6894.76. Used to translate US-customary engineering data into the SI form scientific publications and finite-element models default to.
PSI to Torr Converter
torr = psi × 51.71493
1 psi = 51.7149 torr. Comes up whenever a psi-calibrated regulator meets a vacuum system displaying in torr or mmHg — rotovaps, vacuum ovens, leak-test rigs.
Stokes to Centistokes Kinematic Viscosity Converter
cSt = St × 100
Multiply stokes by 100 to get centistokes. The arithmetic only matters when older CGS viscometer data has to land alongside modern cSt-based lubricant specifications.
Torr to Atmospheres Converter
atm = torr / 760
Convert torr to atmospheres by dividing by 760. Exact by definition — the torr was pinned to 1/760 of a standard atmosphere.
Torr to Bar Converter
bar = torr × 0.001333224
Convert torr to bar by multiplying by 0.001333224. A unit step between vacuum-gauge readings in torr and the bar units IUPAC standard-state thermodynamics use.
Torr to kPa Converter
kPa = torr × 0.133322
Convert torr to kilopascals by multiplying by 0.133322. The step that moves mercury-era pressure readings into the SI-derived units modern chemistry documentation uses.
Torr to Millibar Converter
mbar = torr × 1.33322
Multiply torr by 1.33322 to get millibar. The factor reconciles US-style vacuum-system torr readings with the mbar most European tools display.
Torr to mmHg Converter
mmHg = torr × 1 (effectively identical)
Convert torr to mmHg — numerically identical to within 0.000015%. Both units describe the same vapor-pressure scale with different historical anchors.
Torr to Pascal Converter
Pa = torr × 133.322
Convert torr to pascals by multiplying by 133.322. The translation step for reporting vacuum-range pressures in SI units.
Torr to Pascals Converter
Pa = torr × 133.322
Convert torr to pascals by multiplying by 133.322. Useful any time vacuum-gauge readings and the SI base pressure unit modern chemistry publications use have to agree.
Torr to PSI Converter
psi = torr × 0.019337
Convert torr to psi by multiplying by 0.019337. Needed when lab vacuum-gauge readings crosses into the psi form industrial regulator and valve specs expect.