Pressure Unit Converter: Bar, PSI, Pa, mmHg, ATM Online
Whether you’re a driver checking tire pressure, a diver planning a dive, a meteorologist tracking atmospheric changes, or an engineer designing a hydraulic press, our calculator provides instant answers.
We support lightning-fast conversions between all global units (Bar, PSI, Pascal, atmosphere, torr). Our tool connects everyday life with technical practice. Everything works online, for free, and requires no installation.
Smart Calculations: Why Convert Pressure Units Here?
Pressure is a quantity where the metric system (Bar, Pascal) mixes with the imperial (PSI) and historical (atmosphere, torr) systems. Conversion ratios are not intuitive (did you know that 1 Bar is 14.5 PSI?). Our tool resolves these confusions for you.
- Real-time Calculations: No waiting. Results update dynamically the moment you type a number.
- Universal Application: We can convert pressure in bicycle tires (PSI) as well as extreme pressures in ocean depths or industrial presses (MPa).
- Scientific Accuracy: The widget handles very small or very large numbers. Thanks to scientific notation support (e.g., e-4), you’ll see the precise result even when converting between basic Pascals and Megapascals.
Comprehensive Overview: Understanding Pressure Units
Where do you encounter each unit? Pressure is measured differently depending on whether it’s air, liquid, or blood. Here is a table of relationships:
| Unit | Abbreviation | Approximate Value (in Pascals) | Practical Use |
|---|---|---|---|
| Pascal | Pa | 1 Pa (SI base unit) | Physics, HVAC (very low pressure, multiples are often used). |
| Hectopascal | hPa | 100 Pa | Meteorology. Standard for measuring atmospheric pressure (formerly millibar). |
| Kilopascal | kPa | 1,000 Pa | Construction, tire pressure (e.g., 230 kPa = 2.3 bar). |
| Bar | bar | 100,000 Pa | Tires (Europe), compressors, industry, diving. |
| PSI | psi | approx 6,895 Pa | Tires (USA/UK), cycling, pressure gauges for home water systems. |
| Atmosphere | atm | 101,325 Pa | Physical standard pressure at sea level. |
| Torr (mmHg) | Torr | approx 133 Pa | Medicine (blood pressure), vacuum technology. Corresponds to a millimeter of mercury column. |
Instructions: How to Use the Pressure Converter
Operation is simple, whether you’re at a gas station air compressor or sitting with a physics textbook.
1. Enter the Value
Type the measured value into the left field.
- Tip: The calculator accepts both whole numbers and decimal places (e.g.,
2.5bar).
2. Select Pressure Units
- In the left menu, select the unit you have (e.g., the reading on a pressure gauge – “PSI”).
- In the right menu, select what you need (e.g., “bar”).
- The arrows in the middle are for quick swapping (Swap).
3. Check the “Quick Overview”
This table below the widget provides confirmation.
- If you enter, for example, 100 Pascals, you immediately see that it is 1 hectopascal.
- You also see the conversion to PSI or Torr simultaneously, which is useful for comparing different standards.
Common Mistakes: Tires, Weather, and Blood Pressure
The biggest misunderstandings arise from confusing standards from different parts of the world.
Bar vs. PSI (Tires) This is the most common problem for drivers.
- In Europe, we inflate in Bars (e.g., 2.2 bar).
- In the USA or on many bicycle gauges, PSI (Pounds per Square Inch) is used.
- Caution: 2.2 PSI is an almost empty tire! 2.2 Bar corresponds to approximately 32 PSI. Our converter will show you this conversion immediately and save you a trip to the service station.
Pascal vs. Hectopascal (Weather) In weather forecasts, you hear about pressures around “1013”.
- These are hectopascals (hPa).
- Previously, millibars (mbar) were used. The good news is that 1 hPa = 1 mbar. If you have an old barometer in millibars, you don’t need to convert anything; the value is the same.
Frequently Asked Questions (FAQ)
How many Bars should I inflate if the tire says 35 PSI?
This is a common case with foreign tires or mountain bikes. The relationship is not decimal (1 Bar ≈ 14.5 PSI). If you enter 35 PSI into our converter and convert it to Bar, you'll get a value of approximately 2.4 Bar. This is a safe pressure for most passenger cars.What does "mmHg" mean when measuring blood pressure?
Blood pressure (e.g., 120/80) is not measured in Pascals or Bars, but in the traditional unit of millimeters of mercury (mmHg), sometimes called Torr. Our converter can convert mmHg to kPa, which is sometimes required in modern medical documentation, but doctors still prefer mmHg.What does a result in the form of 1.000e-4 mean?
If you are converting a very small unit (e.g., Pascal) to a very large one (e.g., Megapascal), the result is a number with many zeros after the decimal point. In the example in the image: 100 Pa = 0.0001 MPa. The notatione-4 is scientific format and tells you: "move the decimal point 4 places to the left". This ensures that the result fits on the screen and is mathematically precise.