--- title: "Pressure Conversion Guide: PSI, Bar, kPa, atm & mmHg | ShoutingNow" description: Convert PSI, bar, kilopascals, pascals, atmospheres, and mmHg with pressure conversion formulas, tables, worked examples, and free converters. url: "https://shoutingnow.com/guides/unit-conversion-guide/pressure-conversion/" image: "https://shoutingnow.com/wp-content/uploads/2026/07/Pressure-Conversion-Guide-PSI-Bar-Pascal-atm-mmHg-1024x683.webp" --- # Pressure Conversion Guide: PSI, Bar, kPa, atm & mmHg **Pressure conversion** shows up on tire sidewalls, compressor gauges, weather maps, and lab vacuum lines. PSI, bar, kilopascals, pascals, atmospheres, and mmHg all measure force per area, but labels rarely agree on one unit. This guide covers pressure conversion formulas and tables for the pairs people actually need, then links ShoutingNow’s pressure tools. On this page 13 1. 1 What pressure conversion is (and why gauges disagree) 2. 2 Plain-language pressure formulas 3. 3 Pressure conversion tables PSI to bar and kPa 4. Selected absolute references [ 4 Worked examples ](#worked-examples) 1. Example 1, tire pressure from a metric sticker 2. Example 2, compressor gauge to kilopascals 3. Example 3, mmHg to atmospheres [ 5 Common pressure conversion mistakes ](#common-pressure-conversion-mistakes) [ 6 Pressure converter tools ](#pressure-converter-tools) [ 7 Related reading ](#related-reading) [ 8 Frequently asked questions ](#sn-section-faqs) Show 3 more sections **Convert pressure now:** [Open the free Pressure Converter](https://shoutingnow.com/tools/pressure-converter/), PSI, bar, kPa, Pa, atm, mmHg, and more. No sign-up required. ## What pressure conversion is (and why gauges disagree) Pressure is force spread over an area. Converting pressure rewrites the same reading in another unit: tire PSI to bar, weather millibars to kilopascals, or blood-pressure mmHg to another scale for a report. The SI base unit is the pascal (Pa); kilopascals and megapascals are everyday SI multiples. PSI remains common in the US; bar is common on European gauges; mmHg appears in medicine and older vacuum work; atm is a convenient atmospheric reference. For how those units show up on tires, industrial gauges, and science contexts, without replacing this conversion guide, read [understanding pressure units](https://shoutingnow.com/blog/understanding-pressure-units/). ## Plain-language pressure formulas - PSI → bar: multiply PSI by ≈ 0.0689476. - Bar → PSI: multiply bar by ≈ 14.5038. - PSI → kPa: multiply PSI by ≈ 6.89476. - kPa → PSI: divide kPa by ≈ 6.89476 (or multiply by ≈ 0.145038). - Bar → kPa: multiply bar by 100 (exact: 1 bar = 100 kPa). - atm → Pa: 1 atm = 101,325 Pa exactly (standard atmosphere). - mmHg → atm: divide mmHg by 760 (conventional). - Pa → kPa: divide Pa by 1,000. ## Pressure conversion tables ### PSI to bar and kPa PSI bar (approx.) kPa (approx.) 14.7 1.01 101.4 30 2.07 206.8 35 2.41 241.3 100 6.89 689.5 150 10.34 1,034 ### Selected absolute references Unit Approx. equivalent 1 atm 101,325 Pa / 101.325 kPa / 14.696 PSI / 760 mmHg 1 bar 100,000 Pa / 14.5038 PSI 1 mmHg ≈ 133.322 Pa ## Worked examples ### Example 1, tire pressure from a metric sticker A door sticker lists **2.3 bar**. In PSI: 2.3 × 14.5038 ≈ **33.4 PSI**. Inflate to the sticker value, not a round “32 PSI” guess, unless the vehicle manual says otherwise. ### Example 2, compressor gauge to kilopascals A shop gauge reads **90 PSI**. In kPa: 90 × 6.89476 ≈ **620.5 kPa**. Useful when a tool manual is written in SI only. ### Example 3, mmHg to atmospheres A vacuum note lists **38 mmHg**. In atm: 38 ÷ 760 ≈ **0.050 atm**. Use the [mmHg to atmospheres converter](https://shoutingnow.com/tools/mmhg-to-atmospheres-converter/) when you need a quick check. ## Common pressure conversion mistakes - Confusing gauge pressure with absolute pressure (psig vs psia), converters usually treat the number as a unit change, not a gauge/absolute correction. - Mixing bar and atm, they are close (~1.013 bar ≈ 1 atm) but not identical. - Using mmHg factors for water column (mmH₂O) by mistake. - Rounding tire pressures early, convert fully, then round to the gauge’s resolution. ## Pressure converter tools Start with the multi-unit [Pressure Converter](https://shoutingnow.com/tools/pressure-converter/), or jump to a dedicated pair: - mmHg to Atmospheres Converter ## Related reading - Understanding pressure units, tires, gauges, and industrial context - Engineering unit conversion reference, bridges force, power, and pressure - Unit conversion chart & calculator guide, full category map ## Frequently Asked Questions ### How do I convert PSI to bar? Multiply PSI by about 0.0689476, so 35 PSI comes to roughly 2.41 bar. The [Pressure Converter](https://shoutingnow.com/tools/pressure-converter/) makes quick work of it. ### How do I convert bar to PSI? Multiply bar by about 14.5038. 2.3 bar works out to around 33.4 PSI, the classic tire-sticker conversion. ### How many kilopascals are in one PSI? About 6.89476 kPa, so 30 PSI lands near 206.8 kPa. ### Is 1 bar the same as 1 atmosphere? Close, but not exact. 1 atm equals 101,325 Pa exactly, while 1 bar is a round 100,000 Pa. The gap is small enough to ignore casually but matters in precise work. ### When should I read understanding pressure units? [Understanding pressure units](https://shoutingnow.com/blog/understanding-pressure-units/) is better suited for tire, gauge, and industrial context. This guide is the place for conversion formulas and tables. ### Are ShoutingNow pressure converters free? They are, the Pressure Converter and pair tools like mmHg to atmospheres run free with no account. ```json [{"@context":"https://schema.org","@type":"Organization","name":"ShoutingNow","url":"https://shoutingnow.com/","logo":{"@type":"ImageObject","url":"https://shoutingnow.com/wp-content/themes/shoutingnow-theme/assets/images/logo.png"},"sameAs":["https://x.com/makani20","https://www.linkedin.com/in/makani20/","https://post-see.com"],"contactPoint":{"@type":"ContactPoint","contactType":"customer support","email":"support@shoutingnow.com","url":"https://shoutingnow.com/contact/"},"slogan":"Learn. Build. 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