Best Practices

  The unit always follows the amount; for example, 5 g not g 5

  No period is used after the unit abbreviation, because it may be mistaken for the number 1 if written poorly; for example, write 20 mg instead of 20 mg.

  Do not add an s to make the unit plural, because it may be misread for another unit; for example, 5 mL and not 5 mLs

  Separate the amount from the unit so that the number and unit of measure do not run together, because the unit can be mistaken as a zero or zeros, risking a 10-fold to 100-fold overdose; for example 20 mg not 20mg

  Place a space for amounts with more than 4 digits; for example, 1000 units but 10 000 units not 10,000 units and not 10000 units

  Decimals are used to designate fractional amounts; for example 1.5 mL
not 1 mL

  Use a leading zero to emphasize the decimal point for fractional amounts less than 1; without the zero, the amount may be interpreted as a whole number, resulting in a serious overdose; for example 0.5 mg not .5 mg

  Omit unnecessary or trailing zeros that can be misread as part of the amount if the decimal point is not seen; for example 1.5 mg not 1.50 mg

  Do not use the abbreviation g for microgram, because it might be mistaken for mg which is 1000 times the intended amount; for example 150 mcg
not 150 g

  Do not use the abbreviation cc for mL, because the unit can be mistaken for zeros; for example use 500 mL not 500 cc

  Always use the capitalized L to indicate litre. The lower case l is easily confused with the number one (1).



Source: Pickard et al. Dosage Calculations.