Units of Measure

Abstract

The Units of Measure chapter of the 11th edition of the AMA Manual of Style begins with guidance on the International System of Units (SI) and includes an updated SI conversion table (laboratory reference ranges are no longer included because of differences among laboratories worldwide). Conventions related to format, style, and punctuation of units (eg, exponents, plurals, subject-verb agreement, spelling out units of measure, abbreviations, punctuation, hyphens, and spacing) and capitalization and expression of products and quotients of unit symbols are addressed. A detailed description of use of numerals with units is included, as are specific discussions of units of length, area, volume, and mass; temperature; time; visual acuity; pressure; pH; solutions and concentrations; energy; drug doses; laboratory values; and radiation. The list of international currencies and symbols has been updated and expanded. A change in policy to include a space after the number and before degrees Celsius and degrees Fahrenheit follows SI standards.