The Complete Guide to Pressure Conversions

Everything you need to convert pressure units lives on this page: definitions of each unit, exact conversion factors, mental-math shortcuts, and complete tables between the most-used pairs.

Prefer a calculator? Every conversion on this page has an instant, free tool — start at the tools hub or use the links under each unit below.

The units at a glance

Pascal (Pa)

The pascal — one newton per square meter — is the SI pressure unit, named for Blaise Pascal. It is tiny: atmospheric pressure is about 101,325 Pa.

• 1 Pa = 0.001 kilopascals (kPa) — Pascal to Kilopascal converter
• 1 Pa = 0.00001 bars (bar) — Pascal to Bar converter
• 1 Pa = 0.00014504 pounds per square inch (psi) — Pascal to Pound per square inch converter
• 1 Pa = 0.00000987 atmospheres (atm) — Pascal to Atmosphere converter

Kilopascal (kPa)

The kilopascal (1,000 Pa) is the practical metric pressure unit — tire pressures in metric countries are quoted around 220 kPa.

• 1 kPa = 1,000 pascals (Pa) — Kilopascal to Pascal converter
• 1 kPa = 0.01 bars (bar) — Kilopascal to Bar converter
• 1 kPa = 0.145038 pounds per square inch (psi) — Kilopascal to Pound per square inch converter
• 1 kPa = 0.009869 atmospheres (atm) — Kilopascal to Atmosphere converter

Bar (bar)

The bar (100,000 Pa) sits conveniently close to one atmosphere, which made it the favorite of meteorologists and scuba divers.

• 1 bar = 100,000 pascals (Pa) — Bar to Pascal converter
• 1 bar = 100 kilopascals (kPa) — Bar to Kilopascal converter
• 1 bar = 14.5038 pounds per square inch (psi) — Bar to Pound per square inch converter
• 1 bar = 0.986923 atmospheres (atm) — Bar to Atmosphere converter

Pound per square inch (psi)

PSI is the imperial pressure unit of American tire gauges (32–35 psi for cars) and industrial equipment.

• 1 psi = 6,894.76 pascals (Pa) — Pound per square inch to Pascal converter
• 1 psi = 6.8948 kilopascals (kPa) — Pound per square inch to Kilopascal converter
• 1 psi = 0.068948 bars (bar) — Pound per square inch to Bar converter
• 1 psi = 0.068046 atmospheres (atm) — Pound per square inch to Atmosphere converter

Atmosphere (atm)

The standard atmosphere (101,325 Pa) represents average sea-level air pressure — the natural reference for diving depth and chemistry.

• 1 atm = 101,325 pascals (Pa) — Atmosphere to Pascal converter
• 1 atm = 101.325 kilopascals (kPa) — Atmosphere to Kilopascal converter
• 1 atm = 1.0132 bars (bar) — Atmosphere to Bar converter
• 1 atm = 14.6959 pounds per square inch (psi) — Atmosphere to Pound per square inch converter

Every conversion formula

The table below lists the exact formula for every pressure pair we support. All factors derive from the SI definitions of the units, so chaining them never introduces error.

One-line cross reference: every unit in every other unit

The complete pairwise reference — every supported pressure unit expressed in each of the others:

• 1 pascal = 0.001 kilopascals
• 1 pascal = 0.00001 bars
• 1 pascal = 0.00014504 pounds per square inch
• 1 pascal = 0.00000987 atmospheres
• 1 kilopascal = 1,000 pascals
• 1 kilopascal = 0.01 bars
• 1 kilopascal = 0.145038 pounds per square inch
• 1 kilopascal = 0.009869 atmospheres
• 1 bar = 100,000 pascals
• 1 bar = 100 kilopascals
• 1 bar = 14.5038 pounds per square inch
• 1 bar = 0.986923 atmospheres
• 1 pound per square inch = 6,894.76 pascals
• 1 pound per square inch = 6.8948 kilopascals
• 1 pound per square inch = 0.068948 bars
• 1 pound per square inch = 0.068046 atmospheres
• 1 atmosphere = 101,325 pascals
• 1 atmosphere = 101.325 kilopascals
• 1 atmosphere = 1.0132 bars
• 1 atmosphere = 14.6959 pounds per square inch

Real-world reference points

Pressure anchors: sea-level atmosphere is 101.325 kPa (14.7 psi, 1.013 bar), car tires run 30–35 psi (about 2.2 bar), a bicycle tire 60–100 psi, an espresso machine brews at 9 bar, and every 10 meters of water depth adds about one atmosphere of pressure.

Most-used conversion tables

Pound per square inch to Bar

Pascal to Kilopascal

Kilopascal to Pascal

Kilopascal to Bar

Bar to Kilopascal

Bar to Pound per square inch

Pound per square inch to Atmosphere

Atmosphere to Pound per square inch

Common mistakes to avoid

Pressure errors usually come from absolute versus gauge readings — tire gauges show pressure above atmospheric, so "32 psi" is really 46.7 psi absolute — and from mixing bar with psi when inflating tires abroad; over-inflating by reading a bar target as psi is a common and dangerous mix-up.

Tips for accurate conversions

• Round once, at the end. Chaining conversions and rounding each step compounds error surprisingly fast.
• Watch for regional unit variants. Some unit names have US and imperial variants with different sizes — always check which one your source means.
• Estimate first, then compute. A rough mental figure catches order-of-magnitude mistakes before they end up in your work.
• Use exact factors for anything official. The factors in this guide are the internationally defined values, not approximations.

Frequently asked questions

Which pressure unit should I use?

Use the unit your audience expects: metric units for international and scientific audiences, US customary units for American everyday contexts. When in doubt, give both — "5 km (3.1 mi)" style.

Are these conversion factors exact?

Yes. Every factor on this page comes from the internationally agreed definition of the units involved (most were fixed by treaty in 1959 or by SI definition), so the only inaccuracy is the rounding you choose for the final answer.

Can I use these tables offline?

Yes — print this page or save it as a PDF. The tables are computed from exact factors and will not go out of date.