This blog addresses the last set of principles on drafting numbers. Subsequent blogs will deal with including fractions in a contract, the reference to ranges of figures, dating and timing.
12) Use figures in a combination with units of measurement that are denoted by a symbol or an abbreviation.
- 250 kW or two hundred and fifty kilowatts
- 205 μg or two hundred and five micrograms
- 5 °C or five degrees Celsius
The opposite does not hold. If the units of measurement are spelled out, the numbers may be written with figures:
- 250 kilowatts, 500 metres.
13) In contract clauses, use the official currency abbreviation (e.g., EUR, USD, GBP) with the related amounts (that appear in figures).
This principle applies also to the use of figures in tables, formulas and texts in which figures appear largely. Similarly, prefer the use of EUR to the €-sign (but if you use €, close it up with the figure). Example:
- EUR 50 or one hundred euro
The official plural of euro is euros. Do not capitalise euro (i.e., not Euro). The official notation of U.S. Dollars is USD and not US$ even though various style guides recommend its use in combination with figures (note that U.S. is otherwise abbreviated by points).
14) Reserve the word amount for valuations and prices only. When applicable, the contract drafter determines unit measurements.
For example, refer to numbers of persons or companies but not amounts of persons or companies (the figure of speech is just not a stylistic masterpiece).
With figures, use a person or per person, a year or per year, not per caput, per capita or per annum. Also, prefer the use of percent or per cent instead of the %-sign. Write percentage, never write %age (consider also using proportion or share).
In most non-American contexts, prefer hectares to acres, kilometres (or km) to miles, metres to yards, litres to gallons, kilos to lb, tonnes to tons, Celsius to Fahrenheit. Exceptions apply for those units of measurement that are determined by international market standards; for example, oil is measured by barrels and gallons (there are 3.78541 liters in a gallon and 42 U.S. gallons in a barrel).
In a U.S. context, more familiar measurements can be used as well. Be aware, however, that American pints, quarts and gallons are smaller than their British counterparts.
 The normalised official abbreviations are listed in ISO 4217.