Pressure Converter
Convert pressure values between Pascals, atmospheres, bar, PSI, torr (mmHg), and kilopascals. Essential for engineering, meteorology, tire pressure, scuba diving, and scientific calculations requiring accurate pressure unit conversions.
This free online pressure converter provides instant results with no signup required. All calculations run directly in your browser — your data is never sent to a server. Enter your values below and see results update in real time as you type. Perfect for everyday calculations, homework, or professional use.
The pressure to convert
Source pressure unit
Target pressure unit
How to Use This Calculator
Enter your input values
Fill in all required input fields for the Pressure Converter. Most fields include unit selectors so you can work in your preferred unit system — metric or imperial, whichever matches your problem.
Review your inputs
Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors and can produce results that are off by factors of 2, 10, or more.
Read the results
The Pressure Converter instantly computes the output and displays results with units clearly labeled. All calculations happen in your browser — no loading time and no data sent to a server.
Explore parameter sensitivity
Try adjusting individual input values to see how the output changes. This is a quick and effective way to develop intuition about how different parameters influence the result and to identify which inputs have the largest effect.
Formula Reference
Pressure Converter Formula
See calculator inputs for the governing equation
Variables: All variables and their units are labeled in the calculator interface above. Input fields accept values in multiple unit systems — select your preferred unit from the dropdown next to each field.
When to Use This Calculator
- •Use the Pressure Converter when you need accurate results quickly without the risk of manual computation errors or unit conversion mistakes.
- •Use it to verify calculations made by hand or in spreadsheets — an independent check can catch errors before they lead to costly decisions.
- •Use it to explore how changing input parameters affects the output — a quick way to develop intuition and identify the most influential variables.
- •Use it when collaborating with others to ensure everyone is working from the same numbers and applying the same assumptions.
About This Calculator
The Pressure Converter is a free, browser-based calculation tool for engineers, students, and technical professionals. Convert pressure values between Pascals, atmospheres, bar, PSI, torr (mmHg), and kilopascals. Essential for engineering, meteorology, tire pressure, scuba diving, and scientific calculations requiring accurate pressure unit conversions. It implements standard formulas and supports both metric (SI) and imperial unit systems with automatic unit conversion. All calculations are performed instantly in your browser with no data sent to a server. Use this calculator as a quick reference and sanity-check tool during design, analysis, and learning. Always verify results against primary engineering references and applicable standards for any safety-critical application.
About Pressure Converter
The Pressure Converter enables quick and accurate conversions between the most widely used pressure units across science, engineering, and everyday applications. Pascals and kilopascals are the SI units found in physics and meteorology. Atmospheres provide an intuitive reference for ambient conditions. Bar is common in European industrial and weather contexts. PSI dominates tire pressure and hydraulic systems in the United States. Torr (millimeters of mercury) appears in vacuum science and medical blood pressure readings. This calculator converts between all six units using Pascals as the base.
The Math Behind It
Formula Reference
Pressure Conversion via Pascals
result = value * toPa[from] * fromPa[to]
Variables: value = input pressure, toPa = factor to Pascals, fromPa = factor from Pascals
Worked Examples
Example 1: Tire Pressure: PSI to kPa
Convert 32 PSI tire pressure to kilopascals.
32 PSI equals approximately 220.63 kPa.
Example 2: Standard Atmosphere to Torr
Convert 1 atm to Torr.
1 atmosphere equals exactly 760 Torr by definition.
Common Mistakes & Tips
- !Confusing gauge pressure with absolute pressure. A tire gauge reading 32 PSI means 32 PSI above atmospheric pressure; the absolute pressure is about 46.7 PSI.
- !Using millibars when hectopascals are meant. They are numerically identical (1 mbar = 1 hPa), but the SI-preferred unit is hectopascal.
- !Rounding Torr to mmHg as if they are exactly equal. They differ by about 0.000015%, which matters only in high-precision work but is worth noting.
- !Forgetting that vacuum pressures are reported as negative gauge pressures or as absolute pressures below 1 atm.
Related Concepts
Used in These Calculators
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Frequently Asked Questions
What is standard atmospheric pressure?
Standard atmospheric pressure is defined as 101,325 Pa (101.325 kPa), which equals 1 atm, 1.01325 bar, 14.696 PSI, or 760 Torr. This is the average pressure at sea level at 15 degrees Celsius.
Why are there so many pressure units?
Different fields developed their own units before standardization. Meteorology used inches or millimeters of mercury (barometer readings), engineers used PSI (force per area in imperial units), physicists adopted Pascals (SI), and chemists used atmospheres as a convenient reference. Legacy systems persist because of the cost and risk of switching.
What pressure is considered a vacuum?
Any pressure below atmospheric is a partial vacuum. Low vacuum is 1-100 kPa absolute, medium vacuum is 0.1-1000 Pa, high vacuum is below 0.1 Pa, and ultra-high vacuum is below 0.0001 Pa. Perfect vacuum (0 Pa) is theoretically impossible to achieve.