PSI to MPa Converter
Professional pressure conversion between pounds per square inch and megapascals
Pressure Converter
PSI to MPa
MPa to PSI
Batch Conversion
Common PSI to MPa Conversions
This table provides frequently referenced pressure conversions between psi and MPa for engineering, hydraulic, and pneumatic applications.
| PSI | MPa | Common Application |
|---|---|---|
| 10 psi | 0.069 MPa | Low-pressure pneumatics |
| 50 psi | 0.345 MPa | Residential water systems |
| 100 psi | 0.689 MPa | Air compressor output |
| 150 psi | 1.034 MPa | Steam boiler systems |
| 500 psi | 3.447 MPa | Industrial hydraulics |
| 1000 psi | 6.895 MPa | High-pressure hydraulics |
| 2000 psi | 13.790 MPa | Pressure vessels |
| 3000 psi | 20.684 MPa | Heavy-duty hydraulic systems |
| 5000 psi | 34.474 MPa | Waterjet cutting systems |
| 10000 psi | 68.948 MPa | Ultra-high-pressure applications |
Conversion Formulas and Methods
PSI to MPa Formula
Formula: de>MPa = psi × 0.00689476
Alternative: de>MPa = psi ÷ 145.038
The conversion factor 0.00689476 derives from the relationship between imperial and metric pressure units. One pound per square inch equals 6,894.76 pascals, and one megapascal equals one million pascals.
MPa to PSI Formula
Formula: de>psi = MPa × 145.038
Alternative: de>psi = MPa ÷ 0.00689476
Step-by-Step Conversion Process
Converting 2,500 psi to MPa:
- Start with the pressure value: 2,500 psi
- Multiply by the conversion factor: 2,500 × 0.00689476
- Perform the multiplication: 17.2369 MPa
- Round to appropriate precision: 17.24 MPa
Converting 15 MPa to psi:
- Start with the pressure value: 15 MPa
- Multiply by the conversion factor: 15 × 145.038
- Perform the multiplication: 2,175.57 psi
- Round to appropriate precision: 2,176 psi
Pressure Unit Comparison
PSI (Pounds per Square Inch)
System: Imperial/US Customary
Symbol: psi, lb/in², lbf/in²
Definition: Force of one pound-force applied to one square inch
Common in: North America, UK legacy systems, automotive tyres, HVAC
MPa (Megapascal)
System: International System (SI)
Symbol: MPa
Definition: One million pascals (1 MPa = 1,000,000 Pa)
Common in: Engineering specifications, material science, European standards
Note: In the UK, both psi and MPa are frequently employed. The imperial psi remains prevalent for tyre pressure, compressed air systems, and legacy equipment, whilst MPa is standard for engineering documentation, materials testing, and compliance with European regulations.
Related Pressure Units
Understanding the relationship between psi, MPa, and other pressure units helps in various technical contexts.
| Unit | Equivalent to 1 PSI | Equivalent to 1 MPa |
|---|---|---|
| Pascal (Pa) | 6,894.76 Pa | 1,000,000 Pa |
| Kilopascal (kPa) | 6.895 kPa | 1,000 kPa |
| Bar | 0.0689 bar | 10 bar |
| Atmosphere (atm) | 0.0680 atm | 9.869 atm |
| Torr (mmHg) | 51.715 torr | 7,500.6 torr |
| ksi (kilopound per sq in) | 0.001 ksi | 0.145 ksi |
Industry Applications
Hydraulic Systems
Hydraulic equipment typically operates between 1,000-5,000 psi (6.9-34.5 MPa). Mobile hydraulics for construction machinery often reach 3,000-5,000 psi, whilst industrial presses may exceed 10,000 psi (69 MPa) for metal forming operations.
Pneumatic Systems
Compressed air systems commonly operate at 80-120 psi (0.55-0.83 MPa) for general industrial applications. Workshop air compressors deliver 90-150 psi, whilst specialised pneumatic systems may require higher pressures for specific manufacturing processes.
Pressure Vessels and Piping
Pressure vessel design specifications reference both psi and MPa depending on regional standards. ASME codes traditionally employ psi, whilst European PED (Pressure Equipment Directive) specifications utilise MPa for maximum allowable working pressure ratings.
Material Testing
Tensile strength, yield strength, and compressive strength measurements are frequently expressed in MPa for engineering materials. Steel specifications might list yield strength as 250 MPa (36,260 psi), whilst concrete strength is commonly rated between 20-40 MPa (2,900-5,800 psi).
Automotive Applications
Tyre pressure recommendations in the UK traditionally appear in psi (typically 30-35 psi for passenger vehicles), though modern vehicles also display bar or kPa equivalents. Fuel injection systems operate at 40-80 psi (0.28-0.55 MPa) for port injection, whilst direct injection systems reach 2,000-3,000 psi (13.8-20.7 MPa).
Frequently Asked Questions
What is the difference between psi and MPa?
PSI (pounds per square inch) is an imperial unit measuring pressure as force per area, whilst MPa (megapascal) is a metric SI unit equal to one million pascals. One psi equals approximately 0.00689 MPa, and 1 MPa equals roughly 145 psi. Engineers select units based on regional standards and industry conventions.
How do I convert psi to MPa quickly?
Multiply the psi value by 0.00689476 to obtain MPa. For mental approximations, dividing psi by 145 provides a close estimate. For example, 1,450 psi ÷ 145 ≈ 10 MPa. The converter above handles precise conversions instantly.
Which pressure unit is more common in the UK?
The UK employs both systems. PSI remains prevalent for tyre pressure, compressed air equipment, and legacy systems from imperial measurement traditions. MPa dominates in engineering documentation, structural specifications, materials testing, and applications governed by European standards. Manufacturing sectors often maintain dual-unit specifications for international compatibility.
Why are there multiple pressure units?
Different pressure units emerged from distinct measurement systems and historical contexts. The imperial system (psi) developed in Britain and persists in countries with historical ties. The metric system (Pascal, MPa) was designed for scientific consistency and international standardisation. Industries maintain preferred units based on tradition, equipment calibration, and regulatory requirements.
What is ksi, and how does it relate to psi and MPa?
KSI (kilopounds per square inch) equals 1,000 psi. Material strength specifications often employ ksi for convenience when dealing with large values. For instance, structural steel with 36 ksi yield strength equals 36,000 psi or approximately 248 MPa. The conversion is: 1 ksi = 1,000 psi = 6.895 MPa.
How precise should pressure conversions be?
Precision requirements depend on application context. General engineering work typically rounds to 2-3 decimal places for MPa and whole numbers for psi. Critical applications like pressure vessel design, hydraulic system specifications, or safety-critical components may require greater precision. Always verify that conversion accuracy meets applicable codes and standards.
Can I use this converter for gauge pressure and absolute pressure?
Yes, conversion factors between psi and MPa remain constant regardless of whether measurements represent gauge pressure (psig, relative to atmospheric) or absolute pressure (psia, relative to vacuum). However, when converting between gauge and absolute measurements, account for atmospheric pressure: psia = psig + 14.7, or MPa(abs) = MPa(gauge) + 0.101.
What are typical pressure ranges for common equipment?
Domestic water mains: 40-60 psi (0.28-0.41 MPa); car tyres: 30-35 psi (0.21-0.24 MPa); air compressors: 90-150 psi (0.62-1.03 MPa); hydraulic jacks: 2,000-3,000 psi (13.8-20.7 MPa); pressure washers: 1,500-4,000 psi (10.3-27.6 MPa); industrial hydraulics: 1,000-5,000 psi (6.9-34.5 MPa).