Pressure Units Converter

THE PRACTICAL GUIDE · NORMANDIN SYSTEMS

Get more from Pressure Units Converter

Pressure Units Converter expresses the same pressure measurement in another unit. It is useful when a specification, worksheet, instrument, or reference uses a different scale from the one you need. One bar equals 100,000 pascals; a pascal is one newton per square metre. The numerical value changes because the unit changes; the underlying measured quantity stays the same. Gauge pressure is relative to surrounding pressure, while absolute pressure uses a vacuum reference. Changing units does not change that reference. Enter the measurement together with its source unit, then read the equivalent in the destination unit. Keep the full result while doing subsequent calculations and round only when preparing the final report. A converted value cannot be more precise than the original measurement, even when the calculator displays many decimal places.

Guide updated October 13, 2026

How to use this tool

1. Find the bar input row. If a metric-prefixed row is hidden, clear Exclude SI prefixes to reveal the supported prefixed units.
2. Enter 1 into the bar row for the worked example. Editing a row recalculates the other supported unit rows automatically.
3. Read the Pa row; the example should give 100,000 Pa. Keep the unit label with the number when using it elsewhere.
4. Replace the demonstration value with your measurement, preserving its source unit and meaningful precision. Review the relevant physical assumptions before applying the converted value.

SEE IT IN PRACTICE

A worked example

1 bar

100000 Pa

One bar equals 100,000 pascals; a pascal is one newton per square metre.

Pressure combines force and area

A pascal is one newton per square metre, and one bar is exactly 100,000 pascals. This force-per-area relationship explains why changing either the force unit or area unit affects the scale. Keep the complete pressure unit together when entering data. A force value without an area is not yet a pressure and cannot be converted as one.

State absolute, gauge, or differential reference

Absolute pressure is referenced to vacuum, gauge pressure to an ambient reference, and differential pressure to another measured pressure. Zero therefore has different meanings in each context. A correct bar-to-psi or pascal conversion does not resolve an omitted reference. Keep temperature and operating conditions when they matter to a downstream physical calculation, and use the appropriate reference for that formula.

Pressure references matter

A gauge reading of zero does not mean a perfect vacuum; it commonly means the measured pressure equals the surrounding atmospheric pressure. Absolute and differential instruments use other reference points. Write that reference beside a converted value, especially when a downstream formula requires absolute pressure. The numerical scale conversion cannot infer or repair a missing reference condition.

When this tool is useful

• Prepare consistent pressure values for instrument readings.
• Compare pressure specifications with different units without mentally switching between unit systems.
• Check fluid and gas worksheets before adding a value to a report or calculation.

Tips for a better result

• Gauge pressure is relative to surrounding pressure, while absolute pressure uses a vacuum reference. Changing units does not change that reference.
• Use pascals as a common reference when comparing values from several sources; keeping one unit throughout a calculation makes dimensional errors easier to notice.
• Retain meaningful significant figures. Extra decimal places are useful for intermediate arithmetic, but do not imply that the original instrument measured with that precision.

Frequently asked questions