Pressure Converter: Convert PSI, Bar, kPa, MPa & More (Free Tool)
You have a pressure reading in PSI. Your equipment uses bar. Your manual uses kPa. You need to convert.
Pressure units are confusing. PSI, bar, kPa, MPa, atm, torr, mmHg – the list goes on. Different industries use different units. Getting the conversion wrong can cause equipment damage or safety issues.
Today, I give you a free Pressure Converter.
You enter a value in any unit. The calculator shows the equivalent in all common pressure units instantly.
The converter handles:
- PSI (pounds per square inch)
- Bar
- kPa (kilopascal)
- MPa (megapascal)
- atm (atmosphere)
- Pa (pascal)
- torr / mmHg
Let me explain pressure units and how to convert between them.
What is Pressure? (Simple Explanation)
Pressure is force applied over an area.
Pressure = Force ÷ Area
Common units:
- PSI – pounds per square inch (US customary)
- Bar – metric unit (1 bar ≈ atmospheric pressure)
- kPa – kilopascal (1,000 pascals)
- MPa – megapascal (1,000,000 pascals)
- atm – standard atmosphere (pressure at sea level)
- torr / mmHg – millimeters of mercury
Why This Pressure Converter Matters
Here is why you need a pressure converter.
Reason 1: Tire pressure
Car tires in the US use PSI. European cars use bar or kPa. Convert to inflate correctly.
Reason 2: HVAC systems
Refrigerant pressures use PSI (US) or bar (international). Use wrong units, and you overcharge.
Reason 3: Scuba diving
Tank pressure is in PSI (US) or bar (international). Dive computers show bar. Convert to know your air supply.
Reason 4: Medical equipment
Blood pressure is measured in mmHg. Ventilators use cmH2O. Convert between them.
Reason 5: Engineering specs
Pressure vessel ratings may be in PSI or MPa. Compressor specs in bar. Convert to compare.
The Pressure Conversion Formulas
| From | To | Multiply by |
|---|---|---|
| PSI | kPa | 6.89476 |
| PSI | bar | 0.0689476 |
| PSI | MPa | 0.00689476 |
| kPa | PSI | 0.145038 |
| bar | PSI | 14.5038 |
| MPa | PSI | 145.038 |
| atm | PSI | 14.6959 |
| mmHg | PSI | 0.0193368 |
Key reference:
- 1 PSI = 6.89476 kPa
- 1 bar = 100 kPa = 14.5 PSI
- 1 atm = 14.696 PSI = 101.325 kPa
LIVE Pressure Converter
Enter a value in any unit. All other units update instantly.
📊 Pressure Converter
🔧 PSI (psi)
⚡ Bar (bar)
📏 kPa
💪 MPa
🌍 atm
📊 mmHg / torr
📊 Pressure Converter
Convert between PSI, bar, kPa, MPa, atm, and mmHg
🔧 PSI (psi)
⚡ Bar (bar)
📏 kPa
💪 MPa
🌍 atm
📊 mmHg / torr
0%
💡 1 bar ≈ atmospheric pressure at sea level. 1 atm = 14.696 psi.
📐 Key: 1 psi = 6.89476 kPa = 0.0689476 bar = 0.00689476 MPa = 0.068046 atm = 51.715 mmHg
How to Use This Pressure Converter
Step 1: Enter a value in any pressure unit box
Step 2: All other boxes update instantly
Step 3: Read the converted values in the units you need
The converter works for:
- PSI → bar, kPa, MPa, atm, mmHg
- Bar → PSI, kPa, MPa, atm, mmHg
- And any other combination
Real Examples: Different Scenarios
Example 1: Car tire pressure
- US tire spec: 32 PSI
- Convert to bar: 32 × 0.0689476 = 2.21 bar
- Convert to kPa: 32 × 6.89476 = 221 kPa
Example 2: Scuba tank
- Tank pressure: 3,000 PSI
- Convert to bar: 3,000 × 0.0689476 = 207 bar
- Convert to atm: 3,000 × 0.068046 = 204 atm
Example 3: HVAC refrigerant (R-410A)
- Operating pressure: 120 PSI
- Convert to bar: 8.27 bar
- Convert to kPa: 827 kPa
Example 4: Blood pressure
- Reading: 120/80 mmHg
- Convert to PSI: 120 × 0.0193368 = 2.32 psi, 80 × 0.0193368 = 1.55 psi
Pressure Units Reference Table
| Unit | Symbol | Common Use | 1 PSI equals |
|---|---|---|---|
| Pound per square inch | PSI, psi | US tires, hydraulics | 1.0000 |
| Bar | bar | European tires, scuba, industrial | 0.06895 |
| Kilopascal | kPa | Engineering, metric pressure | 6.8948 |
| Megapascal | MPa | High pressure, materials testing | 0.006895 |
| Atmosphere | atm | Chemistry, reference point | 0.06805 |
| Millimeter of mercury | mmHg, torr | Blood pressure, vacuum | 51.715 |
| Pascal | Pa | SI unit (rarely used directly) | 6,894.76 |
Quick Reference Conversions
| PSI | bar | kPa | MPa | atm | mmHg |
|---|---|---|---|---|---|
| 1 | 0.0689 | 6.89 | 0.0069 | 0.0680 | 51.7 |
| 10 | 0.689 | 68.9 | 0.0689 | 0.680 | 517 |
| 15 | 1.034 | 103.4 | 0.1034 | 1.020 | 776 |
| 30 | 2.068 | 206.8 | 0.2068 | 2.041 | 1,551 |
| 50 | 3.447 | 344.7 | 0.3447 | 3.402 | 2,586 |
| 100 | 6.895 | 689.5 | 0.6895 | 6.805 | 5,172 |
| 150 | 10.34 | 1,034 | 1.034 | 10.21 | 7,757 |
| 200 | 13.79 | 1,379 | 1.379 | 13.61 | 10,343 |
Pressure by Application
| Application | Typical Pressure (PSI) |
|---|---|
| Car tire | 30-35 |
| Bicycle tire | 40-80 |
| Truck tire | 80-100 |
| Home water supply | 40-60 |
| Air compressor (home) | 100-150 |
| Air compressor (industrial) | 150-200 |
| Natural gas supply | 0.25-0.5 |
| Propane tank | 100-200 |
| Scuba tank | 3,000-3,500 |
| Hydraulic system | 1,000-5,000 |
| High pressure washer | 1,500-4,000 |
| Paintball gun (CO2) | 800-1,000 |
| Nitrogen tank | 2,000-2,200 |
Gauge Pressure vs. Absolute Pressure
Gauge pressure (psig, barg) – Measured relative to atmospheric pressure. Ignores the 14.7 psi of air around us.
Absolute pressure (psia, bara) – Includes atmospheric pressure. True pressure from absolute zero.
psia = psig + 14.7
bara = barg + 1.013
When it matters:
- Thermodynamic calculations (gas laws)
- Vacuum systems
- Altitude corrections
Frequently Asked Questions (FAQs)
1. How do you convert PSI to bar?
Multiply PSI by 0.0689476. 100 PSI = 6.89 bar.
2. What is the difference between PSI and kPa?
PSI is pounds per square inch. kPa is kilopascals (metric). 1 PSI = 6.89476 kPa.
3. How many PSI is 1 bar?
1 bar = 14.5038 PSI.
4. What is atmospheric pressure in PSI?
14.6959 PSI at sea level.
5. How do you convert mmHg to PSI?
Multiply mmHg by 0.0193368. 760 mmHg = 14.7 PSI.
6. What is a good tire pressure in PSI?
30-35 PSI for most passenger cars. Check your door jamb sticker.
7. What is the pressure in a scuba tank?
About 3,000 PSI (207 bar) for standard tanks. High pressure tanks are 3,500-4,500 PSI.
8. How do you convert MPa to PSI?
Multiply MPa by 145.038. 1 MPa = 145 PSI.
9. What is vacuum in PSI?
Vacuum is pressure below atmospheric. Measured in inches of mercury (inHg) or negative PSI.
10. Why do Europeans use bar instead of PSI?
Bar is metric and decimal-based. 1 bar = 100 kPa = 0.1 MPa. Easier for calculations.
Common Pressure Unit Mistakes
Mistake #1: Confusing PSI and PSIG
PSI is ambiguous. PSIG (gauge) is most common for tires, pipes, and compressors. For absolute pressure, use PSIA.
Mistake #2: Using 14.7 instead of 14.696
The exact conversion is 14.6959. For most uses, 14.7 is fine. For precision work, use the exact number.
Mistake #3: Forgetting that 1 bar is NOT 1 atm
1 bar = 100 kPa. 1 atm = 101.325 kPa. They are close but not equal.
Mistake #4: Mixing up bar and barg
Bar gauge (barg) excludes atmosphere. Bar absolute (bara) includes it. The difference is 1.013 bar.
Mistake #5: Assuming PSI and PSI are the same everywhere
PSI is the same unit worldwide. But standards vary (water, oil, gas, air). Always check the fluid.
Scientific Reference: The Pascal
The pascal (Pa) is the SI unit of pressure. 1 Pa = 1 N/m².
Why we don't use it directly:
1 Pa is very small. Atmospheric pressure is 101,325 Pa.
We use prefixes:
- 1 kPa = 1,000 Pa
- 1 MPa = 1,000,000 Pa
Comparison:
- 1 PSI = 6,894.76 Pa
- 1 bar = 100,000 Pa
- 1 atm = 101,325 Pa
Pressure in Different Fields
Meteorology:
- bar and millibar (mbar)
- 1 bar = 1,000 mbar
- Standard pressure: 1013.25 mbar
Medicine:
- Blood pressure: mmHg
- Ventilator pressures: cmH2O (centimeters of water)
- 1 cmH2O = 0.0142 PSI
Diving:
- Bar (most common)
- Atmospheres absolute (ATA)
- 1 ATA = 1 bar (approximate)
HVAC:
- PSI (US)
- kPa (Canada)
- bar (Europe)
Final Thoughts
Pressure conversion is essential for many fields.
My Pressure Converter gives you:
- Instant conversion between 6 common pressure units
- PSI, bar, kPa, MPa, atm, and mmHg
- Real-time updates as you type
- Application-based pressure ranges
Bookmark this page. Use it for tire pressure, scuba diving, HVAC, and engineering.
The next time you need to convert PSI to bar or mmHg to kPa, you will have the answer instantly.
Disclaimer: This is an educational tool. For critical applications, verify with calibrated instruments.
External Links (Authority Backlinks):
- Wikipedia – Pressure{:target="_blank" rel="noopener noreferrer"}
- Wikipedia – Pound per square inch{:target="_blank" rel="noopener noreferrer"}
- Wikipedia – Bar (unit){:target="_blank" rel="noopener noreferrer"}
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