All conversions normalize through the SI pascal (Pa) using NIST-derived factors. Gauge vs absolute offsets are not applied automatically—confirm reference type for tires and weather.

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Pressure Converter — PSI, Bar, kPa & MPa

By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026-06-02· Reviewed by EverydayTools Editorial Team

What is Pressure Converter?

A pressure converter translates values between pressure units by normalizing through pascals (Pa)—the SI base unit. Common inputs include PSI (pounds per square inch) for US tires and pneumatics, bar and kPa for European engineering, MPa for hydraulics, hectopascals (hPa) for weather, and mmHg or torr for medical and vacuum work.

The conversion formula is: target = source × (source unit in Pa ÷ target unit in Pa). For example, PSI to bar uses 1 psi = 68,894.76 Pa and 1 bar = 100,000 Pa, so 1 psi ≈ 0.06895 bar.

EverydayTools shows live equivalents across all supported units, copy-ready results, and gauge-vs-absolute guidance. Calculations run locally in your browser.

How we convert pressure units

Every value is converted to pascals first, then to the target unit—standard SI practice for consistent engineering results.

Formula

pascals = input × (Pa per source unit)
output = pascals ÷ (Pa per target unit)

Assumptions

  • PSI uses the exact conversion 6894.757293168 Pa per lbf/in²
  • Water-column units use conventional 9.80665 Pa/mm at 4°C
  • Gauge vs absolute offsets are not applied—you choose the reference context

Sources

How to use Pressure Converter

  1. Enter a pressure value

    Type a number (e.g. 32 for tire PSI or 1013 for weather hPa). Commas are stripped automatically.

  2. Choose from and to units

    Select units from the dropdowns—PSI to bar, kPa to PSI, MPa to bar, or any pair. Use quick presets for common jobs.

  3. Read the live conversion chart

    The all-unit table updates instantly—every row shows the equivalent value without extra clicks.

  4. Copy result or factor

    Copy the formatted conversion line or the 1:1 factor for documentation. Confirm gauge vs absolute before weather comparisons.

Pressure Converter examples

PSI to bar — car tire (32 psi)

Input

32 psi

Output

2.206 bar · 220.6 kPa · 0.2179 MPa

US tire stickers use PSI; European gauges use bar. Formula: bar = psi × 0.0689476.

kPa to PSI — hydraulic line

Input

700 kPa

Output

101.5 psi · 7 bar · 0.7 MPa

Divide kPa by 6.89476 to get PSI: 700 ÷ 6.89476 ≈ 101.5 psi.

MPa to bar — structural steel spec

Input

0.4 MPa

Output

4 bar · 58.0 psi · 400 kPa

1 MPa = 10 bar exactly (both SI-derived). Multiply MPa by 10 for bar.

Weather — 1013 hPa to inHg

Input

1013 hPa

Output

29.91 inHg · 1.013 bar · 14.69 psi (absolute)

Standard sea-level pressure ≈ 1013 hPa = 29.92 inHg. Weather data is absolute, not gauge.

Who uses Pressure Converter?

Common real-world scenarios where this tool saves time.

Automotive technicians and drivers

PSI to bar tire inflation

Convert sidewall PSI to bar for EU pumps and TPMS displays. Remember tire specs are usually gauge pressure, not absolute.

Mechanical and civil engineers

MPa, bar, and PSI in specifications

Translate hydraulic ratings, concrete curing pressures, and pneumatic system limits between metric and US customary units.

Students and lab technicians

kPa, atm, and mmHg in coursework

Check homework conversions between SI pascals, standard atmospheres, and mercury-manometer units with shown formulas.

Meteorology and aviation

hPa, mbar, and inHg on charts

hPa and mbar are identical (1 hPa = 1 mbar). Convert synoptic values to inHg for US NOAA-style reports.

Reference tables

Common pressure conversion chart

Quick reference for engineering and everyday pressure unit conversion (approximate).

FromToMultiply byExample
1 psibar0.0689532 psi → 2.21 bar
1 barpsi14.50382 bar → 29.0 psi
1 kPapsi0.14504100 kPa → 14.5 psi
1 MPabar100.4 MPa → 4 bar
1 atmpsi14.69591 atm → 14.7 psi
1 kgf/cm²psi14.22Hydraulic specs
1 inH₂OPa249.09HVAC duct static
1 mmHgkPa0.13332120 mmHg → 16.0 kPa
1013 hPainHg0.029531013 hPa → 29.91 inHg

Best practices

Normalize through pascals mentally

Every conversion here uses Pa as the SI bridge. If a result looks wrong, check that you picked gauge vs absolute context—not a unit math error.

Use pair shortcuts for repeat jobs

PSI→bar, kPa→PSI, and hPa→inHg chips set units in one tap—faster than scrolling grouped dropdowns on a busy shop floor.

Confirm gauge vs absolute before weather comparisons

Tire gauges read gauge pressure (zero at atmosphere). Synoptic weather uses absolute hPa/mbar. This tool does not add ~14.7 psi atmospheric offset automatically.

Pick HVAC water-column units for duct static

Duct design specs often quote inH₂O or mmH₂O. Use the HVAC group—not psi—for static pressure checks against manufacturer curves.

Export batch CSV for spec sheets

Paste multiple pressure values (one per line) under Batch convert to download a spreadsheet column in your current From → To units—ideal for hydraulic tables and QA logs.

Common mistakes to avoid

Treating tire PSI as absolute pressure

32 psi on a gauge is gauge pressure. Absolute at sea level would be ~46.7 psia. Do not add atmosphere unless your problem requires absolute values.

Using psi for HVAC duct static

Duct static is usually inH₂O or Pa. 0.5 inH₂O ≈ 124 Pa—very different scale from psi.

Assuming mbar and bar differ by 1000× only in name

mbar equals hPa (100 Pa). bar is 1000 mbar. Double-check which label your datasheet uses.

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Frequently Asked Questions

How do I convert PSI to bar?

Multiply PSI by 0.0689476 to get bar (or divide bar by 14.5038 to get PSI). Example: 32 psi × 0.0689476 = 2.206 bar. Tire pressures are usually gauge PSI, not absolute.

How do I convert bar to PSI?

Multiply bar by 14.5038 to get PSI. Example: 2.2 bar × 14.5038 ≈ 31.9 psi. European tire pumps often display bar; US specs list psi.

How do I convert kPa to PSI?

Divide kPa by 6.89476 (or multiply PSI by 6.89476 for the reverse). Example: 100 kPa ÷ 6.89476 ≈ 14.50 psi. 1 kPa = 1,000 Pa.

How do I convert MPa to bar?

Multiply MPa by 10 to get bar (1 MPa = 1,000,000 Pa; 1 bar = 100,000 Pa). Example: 0.5 MPa = 5 bar ≈ 72.5 psi.

What is the pressure unit conversion formula?

target = source × (pascals per source unit ÷ pascals per target unit). All units are converted through Pa first, which keeps engineering pressure calculator results consistent across SI and imperial names.

What is standard atmospheric pressure?

1 atm = 101,325 Pa = 101.325 kPa = 1.01325 bar = 14.696 psi = 760 mmHg = 760 torr = 1013.25 hPa. Used as a reference in physics and engineering conditions.

What is the difference between gauge and absolute pressure?

Absolute pressure is measured from vacuum (0 Pa). Gauge pressure is relative to local atmosphere. A tire gauge showing 32 psi is gauge—absolute would be roughly 32 + 14.7 ≈ 46.7 psia at sea level.

How do I convert inH₂O to pascals for HVAC duct static?

Select inH₂O as the source unit and Pa or kPa as the target. 1 inH₂O ≈ 249.09 Pa. Typical duct static pressure is 0.25–1.0 inH₂O—use the 0.5 inH₂O preset as a starting point.

What is kgf/cm² (technical atmosphere)?

1 kgf/cm² ≈ 98,066.5 Pa ≈ 0.967 atm ≈ 14.22 psi. Common on Asian hydraulic and pneumatic spec sheets. Select kgf/cm² in the Engineering group to convert to bar or MPa.

Are mbar and hPa the same?

Yes—1 mbar = 1 hPa = 100 Pa. Weather charts use hPa; some EU documents say mbar. Both are available in the Weather group.

How do I share a conversion link?

Use Copy link or Share—your value and units encode into the URL (e.g. ?v=32&from=psi&to=bar) so colleagues open the same conversion instantly.

Can I export pressure conversions to CSV?

Yes. Export all units CSV downloads every equivalent for your current value. Batch convert accepts multiple values (one per line) and downloads a CSV using your From → To units.

How do pinned favorite units work?

Tap Pin next to any unit dropdown to add it to your favorites. Pinned units appear at the top of the list and as quick From/To chips for faster HVAC and shop-floor workflows.

Privacy, accuracy, and trust

Privacy

Pressure Converter keeps inputs on your device—nothing is uploaded to EverydayTools servers for core calculations.

Part of Unit Converters

More free tools for the same workflow.

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Reviewed by EverydayTools Editorial Team on 2026-06-02.