Q:

# What is the difference between PSI and PSIG?

A:

PSI and PSIG are both units of measurement for describing the amount pressure a gas or fluid is exerting. However, PSIG specifies what the measurement is relative to, whereas PSI does not. In both units, the letters "psi" are an abbreviation for "pounds per square inch."

Know More

## Keep Learning

PSIG stands for "pounds per square inch gauge," or gage. PSIG units are relative to atmospheric pressure. The air surrounding Earth exerts pressure on all objects on the surface of the planet. At sea level, this pressure is 14.7 pounds for every square inch column of air. PSIG units use this amount of pressure as a baseline, whereas PSIA units (pounds per square inch absolute) use a vacuum as a baseline because vacuums have a total lack of any atmospheric pressure.

Most measurements of pressure made on the surface of the Earth are actually in PSIG if they do not specify what the pressure being measured is using as a baseline. For example, a basketball pumped up to 8 PSI is actually pumped up 8 PSI units over the ambient atmospheric pressure and would have 22.7 PSI if measured relative to a vacuum.

Sources:

## Related Questions

• A:

To an accuracy of two decimal places, 100 kPa is equal to 14.50 psi. According to the University of Florida, 1 psi = 6.89 kPa, which means that 100 kPa = 100/6.89 psi = 14.50 psi.

Filed Under:
• A:

Pounds per square inch cannot be converted to ft-lbs because psi is a measurement of pressure, whereas ft-lbs is a measurement of total energy. Neither one is in the International System of Units as a primary form of measurement. Psi and ft-lbs are primarily American and British units of measure.

Filed Under:
• A:

Megabytes (MB) and gigabytes (MB) refer to units of measurement indicating how much data a digital storage device can hold, where one gigabyte equals 1,024 megabytes. A megabyte is approximately one million bytes, whereas a gigabyte is about one billion bytes. Megabytes and gigabytes are the most common units of measurement when specifying memory sizes in computers and other electronics.