PSI to kPa Converter

Relationship Between PSI and kPa

The conversion between pounds per square inch (PSI) and kilopascals (kPa) is a fundamental pressure unit conversion between imperial and metric systems.

1 PSI = 6.89476 kPa

Therefore,

1 kPa = 0.145038 PSI

To convert PSI to kPa, we multiply the PSI value by 6.89476.

For example, 30 PSI equals 206.843 kPa, which is a typical car tire pressure.

Quick Reference:
Standard atmospheric pressure at sea level is approximately 14.696 PSI or 101.325 kPa. This conversion is crucial for international equipment specifications, automotive applications (tire pressure), hydraulic systems, and engineering calculations where both imperial (PSI) and metric (kPa) units are commonly used.

Pounds per Square Inch (PSI)

What is PSI?

PSI (pounds per square inch) is a unit of pressure in the imperial and US customary systems. It represents the force in pounds-force applied perpendicular to a surface area of one square inch. PSI is the most common pressure unit in the United States for commercial, industrial, and consumer applications.

Historical Background

PSI evolved from the British imperial system and became the standard pressure measurement in the United States and other countries using imperial units. Despite global metrication efforts, PSI remains deeply rooted in American engineering standards, manufacturing specifications, and everyday applications. The unit's widespread use in the US automotive and industrial sectors has made it a de facto international standard for certain applications.

Common Applications

• Automotive: Tire pressure (30-35 PSI cars, 50-80 PSI trucks, 30-40 PSI motorcycles)
• Hydraulics: Construction equipment (2,000-5,000 PSI), hydraulic brakes (1,000-2,000 PSI)
• Pneumatics: Air compressors (90-150 PSI), air tools (90 PSI), spray guns (40-60 PSI)
• Plumbing: Residential water pressure (40-80 PSI), municipal supply (50-100 PSI)
• Pressure Washing: Consumer (1,500-3,000 PSI), commercial (3,000-8,000 PSI)
• Scuba Diving: Compressed air tanks (3,000-4,500 PSI)
• Gas Systems: Natural gas lines (0.25-60 PSI), propane tanks (100-250 PSI)
• Industrial: Boilers (15-300 PSI), steam systems, compressed gas cylinders
• HVAC: Refrigerant systems (50-400 PSI depending on refrigerant type)
• Fire Safety: Fire extinguishers (100-200 PSI), sprinkler systems (7-30 PSI)

PSI Standards

In the United States, PSI is the legal standard for pressure gauges on consumer and industrial equipment. Most American technical specifications, safety standards (OSHA, ANSI), and equipment ratings are published in PSI. Understanding PSI to kPa conversion is essential for international trade, equipment import/export, and compliance with global standards.

PSIA, PSIG, and PSID

• PSIA (Absolute): Pressure measured relative to perfect vacuum. Used in scientific calculations and high-altitude applications.
• PSIG (Gauge): Pressure measured relative to atmospheric pressure. Most common in practical applications. A tire gauge reading 32 PSIG means 32 PSI above atmospheric pressure.
• PSID (Differential): Pressure difference between two points. Used in filter systems, flow measurements, and HVAC applications.
• Conversion: PSIA = PSIG + atmospheric pressure (~14.7 PSI at sea level)

Kilopascal (kPa)

What is a Kilopascal?

The kilopascal (symbol: kPa) is a unit of pressure in the International System of Units (SI). It equals 1,000 pascals, where one pascal (Pa) is defined as one newton per square meter (N/m²). The kilopascal is the preferred metric unit for most pressure applications because it provides convenient numerical values for everyday measurements.

SI Unit Advantage

As an SI unit, the kilopascal is part of the globally standardized metric system. 1 kPa = 1,000 Pa = 1,000 N/m². This coherent system makes scientific calculations straightforward and eliminates conversion errors. Most countries worldwide use kPa as their standard pressure unit for engineering, manufacturing, and consumer applications.

Global Usage

• Automotive (International): Tire pressure specifications in kPa in most countries (200-250 kPa typical)
• Meteorology: Atmospheric pressure (often in hPa = 0.1 kPa, standard is 101.325 kPa)
• Engineering Standards: International specifications (ISO, IEC) use kPa
• Medical Equipment: Blood pressure monitors, ventilators (increasingly using kPa)
• Industrial Equipment: Pressure ratings for valves, pipes, vessels
• Compressed Air: Industrial compressor specifications (700-900 kPa typical)
• Vacuum Technology: Low-pressure measurements (0.1-100 kPa)
• Food Packaging: Modified atmosphere packaging specifications
• Building Systems: Water pressure, HVAC specifications
• Safety Standards: Pressure vessel ratings, relief valve settings

Practical Values

Common pressure values in kPa provide easy-to-remember reference points: Atmospheric pressure ≈ 101 kPa; Car tire pressure ≈ 200-250 kPa; Typical water pressure ≈ 275-550 kPa; Vacuum cleaner suction ≈ 20 kPa. The kilopascal's range makes it ideal for most everyday pressure measurements without requiring multiple decimal places or very large numbers.

Conversion Benefits

Understanding PSI to kPa conversion enables seamless work across international standards. Equipment manufactured in the US (rated in PSI) needs kPa equivalents for international markets. Conversely, metric specifications must be converted to PSI for US applications. The conversion factor (1 PSI = 6.89476 kPa) is essential for engineers, technicians, and procurement professionals working globally.

PSI to kPa Conversion Table

Common PSI to kPa conversions for reference: