Pressure Converter
Convert pressure values between SI, weather, tire, vacuum, and engineering units. The converter routes every value through pascals and shows the surrounding units in a full comparison table.
Base unit
pascal
Supported units
11
Includes
psi + bar + atm
Live converter
Pressure conversion inputs
Enter a value, choose the source and target units, then inspect the full table for related physical units.
Converted result
101.325 kPa
Input
1 atm
Output unit
kPa
Base method
pascals
Pressure in every supported unit
| Unit | Converted value | Unit name |
|---|---|---|
| Pa | 101,325 | Pascals |
| kPa | 101.325 | Kilopascals |
| MPa | 0.101325 | Megapascals |
| bar | 1.01325 | Bar |
| mbar | 1,013.25 | Millibar |
| atm | 1 | Standard atmospheres |
| psi | 14.6959487755 | Pounds per square inch |
| psf | 2,116.21662369 | Pounds per square foot |
| Torr | 760 | Torr |
| mmHg | 759.999891726 | Millimeters of mercury |
| inHg | 29.9212524019 | Inches of mercury |
Base unit
pascal
Supported units
11
Includes
psi + bar + atm
Convert pressure for tires, weather, labs, and engineering
Gauge readings
Convert psi, kPa, bar, and MPa for tires, compressors, hydraulics, and pressure gauges.
Weather and atmosphere
Compare millibars, kilopascals, atmospheres, and inches of mercury for weather and altitude references.
Lab and vacuum work
Convert Torr, mmHg, pascals, and atmospheres for laboratory and vacuum-pressure notes.
Pressure conversion formula
The converter normalizes pressure to pascals before scaling into the selected target unit.
Working formulas
Base conversion
pascals = value x pascals per source unit
Every input pressure is first converted into pascals.
Target value
target value = pascals / pascals per target unit
The pascal value is divided by the target unit factor.
Standard atmosphere
1 atm = 101325 Pa
The standard atmosphere anchors atm, Torr, and related references.
Symbols
- Pa - pascal
- The SI-derived pressure unit used as the base route.
- factor - pressure factor
- The number of pascals represented by one selected unit.
Pressure factors, reference conditions, and safe labels
The converter calculates a requested value through pascals and generates a table for that input. It is not a fixed lookup chart, and it does not infer whether an unlabeled reading is gauge, absolute, or differential pressure.
What the factors mean
The pascal is one newton per square metre. SI prefixes are exact: 1 kPa is 1,000 Pa and 1 MPa is 1,000,000 Pa. One standard atmosphere is exactly 101,325 Pa, and this registry defines 760 Torr as that same pressure.
The displayed psi and mercury-column factors follow the documented unit definitions stored in the converter. A mercury-column label can carry conventional reference conditions, so preserve the original label instead of treating every pressure row as an interchangeable instrument reading.
Worked conversion: one standard atmosphere
1 atm = 101,325 Pa = 101.325 kPa = 760 Torr
These values come from the exact standard-atmosphere relationship used by the converter. A weather or gauge observation near this value still has its own instrument resolution and pressure type.
Keep pressure type with the number
The converter formats results to at most 12 significant digits so factor calculations remain useful without exposing floating-point artifacts. Round the copied value to the resolution of the gauge, sensor, or source specification.
Gauge pressure is measured relative to ambient pressure, while absolute pressure is measured relative to vacuum. Converting the unit does not change one type into the other; that requires the applicable reference pressure.
Use this live converter for a specific reading and its full comparison table. For engineering work, carry the pressure type and source conditions into the receiving calculation or report.
Continue to the force converter for load valuesLimits to keep with the result
- No ambient-pressure value is added or subtracted, so gauge and absolute readings must be identified before use.
- The tool converts units only; it does not evaluate pressure-vessel, tire, vacuum-system, or process safety limits.
- Keep psf, psi, mmHg, inHg, and Torr labels intact because similar-looking numbers may describe different scales or conventions.
Why pressure conversion needs clear labels
Many contexts in one table
- The converter includes SI pressure units, bar, atmospheres, psi, psf, Torr, mmHg, and inHg.
- Weather-style and gauge-style units can be compared without switching tools.
- The table helps users see scale differences between pascals, kilopascals, psi, and bar.
Pascal-based method
- Every pressure conversion is normalized to pascals first.
- The standard atmosphere relationship is visible in the formula section.
- Torr and mercury-column units are labeled separately to reduce ambiguity in lab notes.
Useful for pressure-sensitive work
Mechanical systems
Convert psi, kPa, bar, and MPa for tires, pumps, compressors, hydraulics, and gauges.
Weather references
Compare mbar, kPa, atm, and inHg when reading forecasts and barometric pressure values.
Labs and vacuum
Convert pascals, Torr, mmHg, and atmospheres for vacuum systems and laboratory references.
How it works in three quick steps.
Enter pressure
Type a pressure from a gauge, tire label, weather report, lab note, or engineering specification.
Choose source and target units
Select pascals, kilopascals, bar, atmospheres, psi, Torr, millimeters of mercury, or related units.
Review the pascal table
Use the full table to compare the same pressure across SI, weather, vacuum, and inch-pound units.
Save pressure conversions with context
Copy selected result
Copy the source-to-target pressure result with labels for reports, tickets, and lab notes.
Print the pressure table
Print all supported units when comparing gauge, weather, vacuum, and SI pressure values.
Reference the formula
Use the pascal formula notes to explain which pressure factor was applied.
Frequently Asked Questions
How does the pressure converter calculate results?
What pressure units are supported?
How many pascals are in one atmosphere?
Is psi the same as psf?
When should I use kPa instead of psi?
Related physical unit converters
About this pressure converter
Pressure units appear in several worlds at once. A tire label may show psi and kPa, a forecast may use millibars or inches of mercury, a lab note may use Torr or mmHg, and an engineering specification may use pascals, kilopascals, megapascals, or bar. This converter keeps those units in one pascal-based workflow.
The page separates similar-looking labels such as psi and psf, and it keeps atmosphere, Torr, and mercury-column units visible for laboratory and weather work. That matters because pressure mistakes can change equipment settings, experimental conditions, and safety margins.
The formula section shows the pascal route so the conversion can be checked. This is especially useful when copying pressure values into reports, tickets, calculations, or specifications where the unit label is as important as the number.
Who maintains this page
Ownership and review
Written and maintained by the Toolarithm editorial team. No review date is shown without a maintained editorial record. No independent professional review is claimed.
Methodology
Conversion factors are normalized to canonical units and checked in both directions. Exact definitions and offset formulas are preferred over rounded lookup values.
Read the editorial methodologyDates and sources
Review dates change only after a substantive method or content check.
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