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Calcimator

Universal Pressure Converter

Convert across many related units. Enter your value and which unit it uses.

Pressure is force spread over area, and the ten columns on this page exist because a dozen trades each settled on a different scale for it: psi in hydraulics and tyres, bar across European industry, mmHg at the bedside, torr in vacuum work, inches of mercury in aviation and weather, inches of water column in duct balancing, and pascals wherever SI rules. The pascal is the base. Several factors are exact by definition — the standard atmosphere is precisely 101,325 Pa and the bar precisely 100,000 Pa — while others encode a physical reference: inH2O at 249.089 Pa assumes water near 4 °C, and shifting that reference to 60 °F moves it by about a tenth of a percent. Note that mmHg and torr are given the same 133.322 Pa factor, so those two columns will always agree here even though the strict definitions differ by roughly one part in seven million. The omission that actually bites is gauge versus absolute. Nothing on this page knows which you have. A tyre reading of 32 psi is gauge, meaning 32 above ambient, and its absolute equivalent is nearer 46.7 psia; the converter will faithfully scale whichever number you type without adding or removing an atmosphere for you.

Convert

Results

Pa
1
kPa
0.001
bar
0.00001
psi
0.000145
atm
0.00001
mmHg
0.007501
inHg
0.000295
inH2O
0.004015
torr
0.007501
MPa
0.000001
As Pa
1
How to Use This Calculator
  1. Enter Value, Input unit, and Pa.
  2. Set kPa, bar, and psi.
  3. Adjust atm, mmHg as needed.
  4. Review the Pa result.
  5. Use kPa and bar to inform your decision.

How the result changes with Value

ValuePa
0.40.4
1.41.4
2.62.6
3.63.6

What each input means

Value
Numeric amount in the selected unit.
Input unit
The unit your input value is expressed in.

How this is calculated

Formula

Converted Pressure = Input × (From Factor / To Factor), base unit: pascals (Pa)

Engine last updated . Checked against 2 independently-derived tests how we verify calculators.

Frequently Asked Questions

Are the results gauge pressure or absolute pressure?

Neither, strictly — they are whatever you fed in. The maths is a pure scaling, so a gauge reading stays gauge and an absolute reading stays absolute. To move between them, add or subtract the local atmospheric pressure, near 101,325 Pa at sea level, yourself.

Why do mmHg and torr never differ?

Both are assigned 133.322 Pa on this page. The strict definitions do diverge, by something like one part in seven million, which is far below the precision of any instrument you would use either unit with, so treating them as equal is standard practice.

What does an inch of water column actually represent?

The pressure exerted by a one-inch head of water, about 249.089 Pa. It is the working unit for duct static pressure and gas appliance manifolds because typical values there are a few hundred pascals, far too small to read comfortably in psi.

Is the standard atmosphere the same as the pressure outside right now?

Rarely. The 101,325 Pa figure is a fixed reference, not a measurement. Real sea-level pressure swings by several percent with weather, and altitude drops it steeply — Denver averages closer to 84,000 Pa on an ordinary day.

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

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