Pressure Converter
Convert pressure across SI and other common units. Distinguish absolute and gauge readings using a reference pressure you enter, and compare both in a unit table.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Convert the reading and the reference pressure to pascals. A gauge reading becomes absolute by adding the reference pressure. Subtract the same reference to obtain gauge pressure, then divide by the selected unit factor.
absolute pressure = gauge pressure + reference pressure; gauge pressure = absolute pressure − reference pressure
Worked example
1 bar absolute equals 100 kPa absolute and about 14.5037738 psi absolute. With the example reference of 101.325 kPa, that reading is −1.325 kPa gauge. A reading of 1 bar gauge at that same reference equals 201.325 kPa absolute.
Assumptions and input details
The example reference is standard atmosphere, not measured local atmospheric pressure. Enter the appropriate reference for your situation. Absolute pressure and reference pressure cannot be negative; gauge pressure may be negative down to minus the reference. Torr is defined as 1/760 standard atmosphere. Conventional mercury and water-column units use the listed NIST factors, including rounded factors where published; actual fluid temperature, density, gravity and instrument uncertainty are not corrected. A mass kilogram is not a pressure unit: kgf/cm² explicitly means kilogram-force per square centimeter.
References: NIST: pressure conversion factors · NIST: absolute and gauge measurements
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Find density, mass or volume from the other two values. Choose international and regional units and inspect the formula and unit-conversion tables.
Convert Celsius, Fahrenheit, kelvin and Rankine. Distinguish actual temperatures from temperature changes, and compare all four scales in a table.
Calculate the volume and surface area of a box, cylinder, sphere or cone. Mix length units, inspect a dimensioned diagram and compare regional volume units.
Reserved advertising space.