kilopascal, kPa

Air pressure is measured in kilopascals (named after Blaise Pascal, philosopher and scientist); the symbol is kPa. Note the upper-case P in the symbol kPa but not in kilopascal.

Leave a space between kilopascal or kPa and the numeral that immediately precedes it, as in 18 kilopascals or 18 kPa. Because the metric (SI) system uses symbols, not abbreviations, the symbol kPa does not contain periods or take an s in the plural form.

• Normal adult blood pressure is below 19/12 kPa, so John’s is too high.

SI usage, followed in scientific and technical writing, prescribes that both the number and kilopascal be written in full (e.g. eighteen kilopascals) or that the numeral be followed by the symbol (e.g. 18 kPa).

• Today’s air pressure is 103.8 kPa.

However, general usage accepts numerals with spelled-out unit names (e.g. 18 kilopascals) to improve comprehension.

• Today’s air pressure is 103.8 kilopascals.

When no specific figure is stated, write kilopascal in full.

• Do you know how to convert kilopascals to pounds per square inch?