Numbers and units
Write numbers the same way on every page: when to spell them out, separators, units of measure, dates, times, and currency.
Spell out zero through nine
Write zero through nine as words, and 10 upward as numerals.
- Correct:
Create three rules. - Correct:
The account allows 100 buckets.
Three cases take a numeral whatever the value: a measurement, a version, and anything the reader types or reads on screen. Set the TTL to 5 seconds, not five seconds.
Use a period for decimals and a comma for thousands
| Rule | Example |
|---|---|
| Period for the decimal separator | 9.5, 3.14159 |
| Comma for thousands | 10,000, 25,456,990 |
| A leading zero below one | 0.5, never .5 |
Portuguese reverses both separators. A translated page writes 10.000 and 9,5, so a number copied across a pair without conversion is wrong in one of them.
Write a unit with its number
- Put a space between the numeral and the unit:
20 MB,60 seconds. - Hyphenate when the measurement modifies a noun:
a 60-second TTL. - Abbreviate only next to a number, and never follow the abbreviation with a period:
20 MB, not20 MB.ortwenty MB.
Every value in a table carries its unit. A cell holding 100 leaves the reader choosing between megabytes, seconds, and requests. Reference treats a limit without a unit as an incomplete fact.
MB and MiB are different numbers. Write the unit the product states and never convert between decimal (kB, MB, GB) and binary (KiB, MiB, GiB) forms. The same applies to rates: Gbps counts bits and MB/s counts bytes, eight times apart, so keep the form the product uses.
A limit is exact and is never rounded. Round only an illustrative figure, and mark it: about 200 ms.
Use an en dash for a negative number
Write –40 with an en dash, not a hyphen. The rule applies to prose: in code, commands, and any value the reader copies, keep the ASCII hyphen-minus — a pasted –40 does not parse. Punctuation covers the other dash rules.
Write an ordinal without a suffix beyond the number
Write first and second as words. In a numeral, write 1st, never 1stly or firstly.
Format a date only where a date belongs
Dates appear in changelogs and nowhere else, which Word choice states as a rule. A date anywhere else ages the page.
Where a date is allowed, spell the month out and order it month, day, year: July 10, 2026.
- Incorrect:
7/10/2026 - Incorrect:
July 10th, 2026 - Correct:
July 10, 2026
A numeric date reads as month-first in the United States and day-first almost everywhere else, so it means two things at once.
Write a time in the 24-hour clock or with AM and PM
Capitalize AM and PM and put a space before them: 10:45 AM. Portuguese pages use the 24-hour clock: 10:45, 18:30.
Do not write 24/7. Write at all times or name the actual availability.
Format currency only on the pricing page
A price, a quota sold by the unit, and a billing metric live on the pricing page alone. Reference forbids restating one on a product page.
Where an amount is allowed, the symbol precedes the number with no space: $1,000.