Last updated: September 16, 2026
Quick answer: Multiply bar by 14.504 to get PSI. 1 bar = 14.504 psi. So 2 bar = 29.0 psi (typical car front tyre), 2.5 bar = 36.3 psi, and 8 bar = 116.0 psi (road bicycle tyre). To reverse, see our PSI to bar converter.
Bar to PSI
Instantly convert bar to psi with fast, accurate, real-time results.
Formula: bar to PSI
PSI (pounds per square inch) and bar are both units of pressure. One bar is defined as exactly 100,000 pascals (Pa). The conversion factor to PSI is:
Examples:
- 1.8 bar × 14.5038 = 26.1 psi (minimum car tyre pressure)
- 2.2 bar × 14.5038 = 31.9 psi (typical car front tyre)
- 2.5 bar × 14.5038 = 36.3 psi (typical SUV / light truck)
- 9 bar × 14.5038 = 130.5 psi (road bike tyre)
Car and truck tyre pressure guide
Recommended tyre pressures vary by vehicle, load, and tyre type. European vehicles typically show pressures in bar on a sticker inside the driver's door or fuel cap; US vehicles use PSI. Here are common conversions:
| Bar | PSI | Typical use |
|---|---|---|
| 1.8 bar | 26.1 psi | Minimum safe passenger car front (light load) |
| 2.0 bar | 29.0 psi | Common small hatchback front tyre |
| 2.2 bar | 31.9 psi | Typical sedan front tyre (EU standard) |
| 2.3 bar | 33.4 psi | Common mid-size car recommendation |
| 2.4 bar | 34.8 psi | Typical sedan or SUV rear tyre |
| 2.5 bar | 36.3 psi | SUV / crossover front tyre |
| 2.7 bar | 39.2 psi | Light van / fully loaded passenger car |
| 3.0 bar | 43.5 psi | Light commercial vehicle (unloaded) |
| 4.0 bar | 58.0 psi | Light truck / delivery van (fully loaded) |
| 8.0 bar | 116.0 psi | Heavy truck / semi trailer steering axle |
Always check your vehicle's door placard or owner's manual for the exact specification. Pressures listed above are for cold tyres (measured before driving more than 1–2 km). Hot tyres read 0.2–0.4 bar (3–6 psi) higher — this is normal.
Bicycle tyre pressure chart
Bicycle pressures range much more widely than car tyres, depending on the discipline. Tyre width also matters: narrower tyres need more pressure to support the same load.
| Bike type / tyre | Typical range (bar) | In PSI |
|---|---|---|
| Road bike (23–25 mm) | 6.5–9.0 bar | 94–130 psi |
| Road bike (28 mm) | 5.5–7.5 bar | 80–109 psi |
| Gravel / cyclocross (32–40 mm) | 2.8–4.5 bar | 41–65 psi |
| Hybrid / commuter (35–45 mm) | 3.0–5.0 bar | 44–73 psi |
| Mountain bike (2.2–2.5 in) hardtail | 2.0–3.0 bar | 29–44 psi |
| Mountain bike (2.3–2.6 in) full-suspension | 1.5–2.5 bar | 22–36 psi |
| Fat bike (3.8–4.8 in) | 0.3–1.0 bar | 4–15 psi |
| E-bike (city) | 3.0–4.5 bar | 44–65 psi |
Other pressure references
Atmospheric and weather pressure
Standard atmospheric pressure at sea level is 1.01325 bar (14.696 psi), often rounded to 1 bar for practical use. Meteorologists use hectopascals (hPa) or millibars (mbar) — where 1 bar = 1,000 mbar = 1,000 hPa. A hurricane with a 900 mbar (0.9 bar / 13.05 psi) central pressure is extremely intense; a high-pressure system sits around 1,020–1,030 mbar (1.02–1.03 bar).
Espresso and coffee machines
| Application | Bar | PSI |
|---|---|---|
| Ideal espresso extraction pressure | 9 bar | 130.5 psi |
| Pre-infusion pressure | 4–6 bar | 58–87 psi |
| Steam wand (milk frothing) | 1.0–1.5 bar | 14.5–21.8 psi |
| Home espresso boiler (max safe) | 15 bar | 217.6 psi |
| Moka pot (stovetop) | 1.5–2 bar | 21.8–29.0 psi |
Industrial and hydraulic systems
| System | Typical pressure (bar) | In PSI |
|---|---|---|
| Garden hose (household) | 2.5–4.5 bar | 36–65 psi |
| Mains water supply (residential) | 2–7 bar | 29–102 psi |
| Scuba cylinder (full) | 200–300 bar | 2,901–4,351 psi |
| Hydraulic excavator arm | 300–350 bar | 4,351–5,076 psi |
| High-pressure cleaning (power washer) | 70–200 bar | 1,015–2,901 psi |
| Aircraft hydraulics (Boeing 787) | 345 bar | 5,000 psi |
Full bar to PSI conversion table
| Bar | PSI | Bar | PSI |
|---|---|---|---|
| 0.1 bar | 1.45 psi | 3.5 bar | 50.76 psi |
| 0.2 bar | 2.90 psi | 4.0 bar | 58.02 psi |
| 0.3 bar | 4.35 psi | 4.5 bar | 65.27 psi |
| 0.5 bar | 7.25 psi | 5.0 bar | 72.52 psi |
| 0.7 bar | 10.15 psi | 5.5 bar | 79.77 psi |
| 1.0 bar | 14.50 psi | 6.0 bar | 87.02 psi |
| 1.2 bar | 17.40 psi | 6.5 bar | 94.27 psi |
| 1.5 bar | 21.76 psi | 7.0 bar | 101.53 psi |
| 1.8 bar | 26.11 psi | 7.5 bar | 108.78 psi |
| 2.0 bar | 29.01 psi | 8.0 bar | 116.03 psi |
| 2.2 bar | 31.91 psi | 8.5 bar | 123.28 psi |
| 2.3 bar | 33.36 psi | 9.0 bar | 130.53 psi |
| 2.4 bar | 34.81 psi | 10.0 bar | 145.04 psi |
| 2.5 bar | 36.26 psi | 11.0 bar | 159.54 psi |
| 2.7 bar | 39.16 psi | 12.0 bar | 174.05 psi |
| 3.0 bar | 43.51 psi | 13.0 bar | 188.55 psi |
| 3.0 bar | 43.51 psi | 14.5 bar | 210.31 psi |
| 3.2 bar | 46.41 psi | 15.0 bar | 217.56 psi |
Frequently asked questions
What is 2.5 bar in PSI?
2.5 bar = 36.26 psi (2.5 × 14.5038 = 36.26). This is a typical recommended pressure for SUV front tyres and many crossovers. Always verify against your vehicle's door placard or owner's manual.
Is 2 bar the same as 29 psi?
Almost exactly. 2 bar × 14.5038 = 29.01 psi — so yes, 2 bar is essentially 29 psi. This is a common minimum-spec pressure for small car front tyres, particularly with lighter loads.
What is the difference between bar and PSI?
Both measure pressure, but use different reference units. PSI (pounds per square inch) is part of the imperial system and is standard in the US. Bar is a metric unit equal to 100,000 pascals, widely used in Europe and in international engineering. The conversion is: 1 bar = 14.5038 psi; 1 psi = 0.0689 bar.
What is 1 bar in PSI?
1 bar = 14.504 psi (to 3 decimal places). Standard atmospheric pressure is 1.01325 bar = 14.696 psi, which is why "1 bar" and "1 atmosphere (atm)" are close but not identical. Gauge pressure readings (like tyre pressures) are measured above atmospheric — so a "0 bar" tyre reading on a gauge means atmospheric pressure, not a vacuum.
How do I convert bar to PSI without a calculator?
Multiply by 15 for a quick approximation: 2 bar ≈ 30 psi, 2.5 bar ≈ 37.5 psi. This is about 3% high, so for critical applications always use the precise factor (14.5038) or a calculator. For tyre inflation, the 3% rounding error is well within normal gauge tolerance.
What is 9 bar in PSI? (espresso pressure)
9 bar = 130.5 psi. This is the standard extraction pressure for espresso machines, first established by Italian coffee standards in the 1940s. Modern "pressure profiling" machines allow baristas to vary between 4–12 bar (58–174 psi) during extraction for flavour adjustment.
Sources and references
- Bureau International des Poids et Mesures (BIPM). The International System of Units (SI). 9th edition, 2019. (Bar defined as 10⁵ Pa.)
- National Institute of Standards and Technology (NIST). Non-SI units accepted for use with the SI. U.S. Department of Commerce.
- Michelin. Correct Tyre Pressure. Michelin UK.
- Istituto Nazionale Espresso Italiano (INEI). Certified Italian Espresso: Technical Parameters. (9 bar extraction pressure standard.)
- European Tyre and Rim Technical Organisation (ETRTO). Standards Manual — Tyre Load and Pressure Tables.
Related converters
Author
Shakeel Muzaffar is the Founder and Editor-in-Chief of MultiCalculators.com, bringing over 15 years of experience in digital publishing, product strategy, and online tool development. He leads the platform's editorial vision, ensuring every calculator meets strict standards for accuracy, usability, and real-world value. Shakeel personally oversees content quality, formula verification workflows, and the platform's commitment to publishing tools that are genuinely useful for students, professionals, and everyday users worldwide.
