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Barometric Pressure Converter.

Convert barometric pressure between standard units.

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01

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Result: 1,013.25

Result

0.00000000

Use Cases

Weather and Meteorology

Convert barometric pressure readings between units commonly used in weather reports, such as HPA, BAR, and ATM, for comparison or data analysis.

Example: Convert 1013 HPA to ATM to compare with standard atmospheric pressure.

Engineering and Industrial Applications

Switch between pressure units like PSI, PSIG, PA, and BAR for equipment specifications, calibration, or process control.

Example: Convert a gauge reading of 30 PSIG to BAR for a pressure vessel rating.

Frequently Asked Questions

What is the difference between PSI and PSIG?
PSI (pounds per square inch) is an absolute pressure unit, while PSIG (pounds per square inch gauge) measures pressure relative to atmospheric pressure. PSIG = PSI - atmospheric pressure (typically 14.7 psi at sea level).
How do I convert barometric pressure from HPA to ATM?
To convert from hectopascals (HPA) to atmospheres (ATM), divide the HPA value by 1013.25, since 1 ATM equals 1013.25 HPA. For example, 1013.25 HPA equals 1 ATM.
Can this converter handle negative pressure values?
Yes, the converter accepts negative values, which are common for gauge pressures below atmospheric (e.g., vacuum). However, absolute units like ATM, BAR, PSI, PA, and HPA should not be negative in physical contexts.

Tips & Common Mistakes

Tips

  • Always double-check the unit you are converting from and to, as PSI and PSIG are often confused.
  • For absolute pressure conversions, use ATM, BAR, PSI, PA, or HPA; for gauge pressure, use PSIG.
  • Remember that 1 ATM = 1013.25 HPA = 1.01325 BAR = 14.6959 PSI.
  • When converting between absolute and gauge units, account for atmospheric pressure (typically 14.7 PSI or 1013.25 HPA).

Common Mistakes to Avoid

  • Confusing PSI with PSIG: PSI is absolute, PSIG is gauge. Using the wrong one can lead to significant errors.
  • Forgetting to adjust for atmospheric pressure when converting between absolute and gauge units.
  • Assuming 1 BAR equals 1 ATM exactly; they differ by about 1.3%.

Last updated: August 13, 2026