Hyphens and Dashes between Numbers
This page is about when to use hyphens and dashes between numbers.
Hyphens between Numbers
Hyphens are used between numbers:
(1) When putting dividers in long numbers (e.g., serial numbers or telephone numbers)
(2) When writing numbers in full.
- two hundred and thirty-two
Note: Hyphenate all numbers between 21 and 99 (less those ending 0, e.g., 50, 60).
(3) When writing fractions in full
Dashes between Numbers
Dashes are used between numbers:
(1) To show ranges
- 0800–0900 hrs
- 10–15 minutes
- 100–120 staff
These are en dashes (the same length as a lowercase "n"). They are shorter than em dashes (the same length as uppercase "M").
Read more about en dashes and em dashes
Nowadays, It's Safe to Use Hyphens in Ranges
Hyphens are not meant to be used for ranges (e.g., 10-12, 1967-
1971). Dashes are used for this purpose. However, given that the hyphen is so easy to find on a keyboard, hyphens have become acceptable for ranges. Only a very strict grammar pedant would pull you up for using hyphens. If this were to happen, you could make a good case for the pedant being out of date.