A standard unit of measure is a unit that is commonly used to indicate the length or mass of an object. Standard units of measure are also used to indicate the passage of time.

• Length is commonly measured in units of metres, centimetres, millimetres, kilometres, etc.
• Mass is commonly measured in units of grams, kilograms, etc.
• Time is commonly measured in units of seconds, minutes, hours, days, weeks, months, years, etc.

The length of a person's foot could be expressed in the standard unit of centimetres.