Gigapascal (GPa)

Metric (SI)Current unit

One billion pascals. Used for the stiffness (Young's modulus) of materials; steel is about 200 GPa.

1 gigapascal = 1,000,000,000 pascals (exactly).

About the gigapascal

Blaise Pascal's name was attached to the SI unit of pressure in 1971, when the 14th General Conference on Weights and Measures adopted it for one newton per square metre. A gigapascal is a billion of them, 10^9 Pa, which is a size that makes sense only for solid materials and deep-Earth conditions, not for weather or tyres.

Materials scientists quote stiffness in it. Wikipedia's table of Young's modulus lists structural steel at about 200 GPa and diamond at 1,220 GPa, while geophysicists use gigapascals for tectonic stresses and pressures inside the planet. Atmospheric pressure of about 101,325 Pa is therefore about 0.0001 GPa, and one gigapascal is roughly 145,000 psi or 145 ksi. A gigapascal also equals one thousand megapascals, the unit in which concrete and steel strengths are usually written.

Sources: Wikipedia: Pascal (unit); Wikipedia: Pounds per square inch

Gigapascal conversion chart

1 gigapascal expressed in every other pressure unit:

More Metric (SI) units

• pascal (pressure)
• kilopascal (pressure)
• hectopascal (pressure)
• megapascal (pressure)
• bar (pressure)
• millibar (pressure)
• standard atmosphere (pressure)
• meter (length)
• kilometer (length)
• centimeter (length)
• millimeter (length)
• micrometer (length)
• nanometer (length)
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• decimeter (length)
• hectometer (length)

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