Pressure Converter
Convert between pascal, kilopascal, megapascal, hectopascal, bar, millibar, PSI, atmosphere, torr, and inches of mercury.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 atm = 14.695949 psi
1 Standard Atmosphere = 14.695949 Pounds per Square Inch
1 Pound per Square Inch = 0.068045964 Standard Atmospheres
1 atm in every supported unit
What is a Pressure Converter?
Pressure is force distributed over an area — the same push applied to a smaller surface produces higher pressure, which is why a needle punctures skin but a flat palm does not. A pressure converter translates a reading in one pressure scale into its equivalent in another, so a barometer reading, a tire gauge, or a lab vacuum measurement can be compared no matter which scale it was taken in.
Unlike most physical quantities, pressure is measured in several genuinely unrelated scales depending on who is using it: the SI world uses pascals and bars, the United States uses PSI for tires and plumbing, meteorologists worldwide report barometric pressure in hectopascals or millibars, and vacuum science and aviation still rely on torr and inches of mercury. Every unit below is defined relative to the pascal, the SI base unit of pressure, so any conversion between them reduces to a single multiplication.
Conversion chart: Standard Atmosphere to Pounds per Square Inch
Conversion table
| Standard Atmosphere (atm) | Pound per Square Inch (psi) |
|---|---|
| 0.01 atm | 0.14695949 psi |
| 0.1 atm | 1.4695949 psi |
| 1 atm | 14.695949 psi |
| 2 atm | 29.391898 psi |
| 3 atm | 44.087846 psi |
| 5 atm | 73.479744 psi |
| 10 atm | 146.95949 psi |
| 20 atm | 293.91898 psi |
| 50 atm | 734.79744 psi |
| 100 atm | 1469.5949 psi |
| 1000 atm | 14695.949 psi |
Supported Units
| Unit | Symbol | In Pascals |
|---|---|---|
| Pascal | Pa | 1 Pa |
| Kilopascal | kPa | 1000 Pa |
| Megapascal | MPa | 1000000 Pa |
| Hectopascal | hPa | 100 Pa |
| Bar | bar | 100000 Pa |
| Millibar | mbar | 100 Pa |
| Pound per Square Inch | psi | 6894.7573 Pa |
| Standard Atmosphere | atm | 101325 Pa |
| Torr | Torr | 133.32237 Pa |
| Inch of Mercury | inHg | 3386.38 Pa |
About These Parameters
- Value
- The pressure reading you want to convert, expressed in the "From" unit. Accepts decimals.
- From Unit
- The pressure scale your input value is currently measured in — for example, PSI on a US tire gauge or hectopascals on a weather report.
- To Unit
- The pressure scale you want the result converted into. Use the swap button to flip From and To instantly.
How Pressure Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to the pascal. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For Standard Atmosphere → Pound per Square Inch: multiply by 14.695949. For example, 1 atm × 14.695949 = 14.695949 psi.
SI vs. Customary Units
The metric units on this page — pascal, kilopascal, megapascal, hectopascal, bar, and millibar — all scale by powers of ten, so converting between them is just moving a decimal point. PSI is a US customary unit built from pounds-force and square inches, unrelated to the metric scale, while torr and inches of mercury are older manometer-based units defined by the height of a mercury column a pressure could support — each needs its own precise multiplier rather than a round decimal shift.
Why Atmospheric Pressure Matters
Standard atmospheric pressure — 101,325 Pa, or 1 atm — is the reference point most pressure units are built around, because it is the pressure every person and machine on Earth's surface experiences by default. Meteorologists track small deviations from this baseline, measured in hectopascals or millibars, to forecast weather: a falling barometer reading signals an approaching low-pressure system and possible storms, while a rising one signals clear, stable conditions.
Example
1 atm equals 14.695949 psi. For scale, that's about 1× standard atmospheric pressure (1 atm, or 1 atm) — roughly the pressure difference a typical car tire holds above the surrounding air (about 32 psi, or 2.2 bar).
Frequently Asked Questions
Why do US tire gauges use PSI?
The United States never mandated metrication, so pounds and inches stayed the default units for everyday measurement, including the pound-force-per-square-inch pressure scale used on tire gauges, plumbing fixtures, and compressed air tools. Most of the rest of the world reads the same measurement in bar or kilopascals.
What's the difference between a bar and an atmosphere?
A bar is a round metric unit equal to exactly 100,000 pascals, chosen for convenient arithmetic; a standard atmosphere is fixed at exactly 101,325 pascals, the measured average air pressure at sea level. The two are close — 1 atm is about 1.01325 bar — but they are defined differently and are not interchangeable in precise scientific work.
How accurate are these conversions?
Every conversion factor used here is the exact, internationally standardized value (e.g. 1 atm = exactly 101,325 Pa, and 1 psi = exactly 6,894.7572931783 Pa) — results are limited only by floating-point display precision, not by rounded conversion constants.