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Number Spans and Year Spans

Number Spans, a.k.a. Number Ranges, Inclusive Numbers, Continuing Numbers

Quick glance

CMS: use en dash 64–68   AP: use hyphen 64-68

CMS: strict rules about number spans  AP: more relaxed

CMS number span rules:

Usually repeat all digits: 3–7, 64–68, 91–115, 191–215
Unless hundreds place doesn’t change: 127–32
But repeat all if first number ends in 00: 100–124
And repeat only one digit if both numbers end in 01–09: 202–6  (some publishers prefer 202–206)

Years follow same rules.

1998–2015
2012–17
2000–2017
2005–8 (or 2005–2008 if publisher prefers)

With from or between, don’t use an en dash: from 2005 to 2008, NOT from 2005–2008 (AP agrees.)

AP:
Short year spans within about 10 years: best to use 1992-96 but fine to use 1992-1996
Repeat all digits for all other numbers (not a strict rule, use your discretion.)

Deeper details

En dashes vs. hyphens

Chicago style: Always use an en dash –, not a hyphen -, with a number span.

AP style: Use a hyphen with a number span. (AP does not use the en dash at all.)

Comma in number or no? 9.55

No commas: page numbers, line numbers, serial numbers, addresses, years.
page 1233   line 1602   14204 Van Street   1200 BC    in 1985

Commas: all other numbers 1,000 and above
1,523 people

AP style: Agrees with Chicago. They also note broadcast frequencies, room numbers, and telephone numbers for no commas.

Number spans (not years)

Concise rules

  • Usually repeat all digits
    • 3–7  14–16  73–76  81–100  91–104  93–112  163–224
  • But repeat 2 digits only if hundreds place doesn’t change.
    • 112–16  204–15  623–84
  • Except when first number ends in 00, then repeat all digits.
    • 100–106  200–210
  • Except when both numbers end in 01–09, then repeat 1 digit only. UNLESS publisher prefers all digits.
    • 203–5 (CMS)      203–205 (If publisher prefers)
  • For 4+ digit numbers, follow same rules, but repeat enough digits to cover the changed part.
    • 1328–33   1593–622
    • Note this slight oddity:
      • 1200–1216 (first number ends in 00, repeat all digits)
      • but 1294–300 (second number ends in 00, repeat only the changed part)
    • If comma in the number, follow same rules, unless the thousands place changes. Then repeat all.
      • 11,296–314 but 11,296–12,123
  • Roman numerals: give both numbers in full
  • BC, BCE, BP (diminishing numbers): give both numbers in full

Rules in a table if you prefer

First number Second number Repeat
Any Hundreds place changes In all cases below, if hundreds place changes, repeat all digits. 164–239
But if 4+ digits, repeat enough digits to cover the changed part. 1523–608  13982–4006
1–99 1–99 All   3–7  5–13  14–16  73–76
1–99 Ends in 00 All   83–100  97–200
1–99 Ends in 01–09 All   83–105
1-99 Ends in 10–99 All   83–110  97–226
Ends in 00 Ends in 00 All   100–200
Ends in 00 Ends in 01–09 All   100–102  100–208
Ends in 00 Ends in 10–99 All   100–110  200–211  300–336
Ends in 01–09 Ends in 00 All   102–200
Ends in 01–09 Ends in 01–09 1 digit only (CMS pref.)   101–2  203–9  1204–5
or All (if publisher prefers)   101–102  203–209  1204–1205
Ends in 01–09 Ends in 10–99 2 digits only    101–10  205–24
Ends in 10–99 Ends in 00 All   194–200
(But for 4+ digits, just repeat changed part: 1194–200  12994–3000)
Ends in 10–99 Ends in 01–09 All   194–201
(But for 4+ digits, just repeat changed part: 1194–201)
Ends in 10–99 Ends in 10–99
 2 digits only    110–11  218–20  364–73

Year spans

  • Repeat all digits for century changes, or if first number ends in 00
    • 1898–1902  1900–1903  2000–2005
  • Repeat 1 digit only if both numbers end in 01–09 UNLESS publisher prefers all digits

    • 1904–5 (CMS)   or   1904–1905 (if publisher prefers)
  • Repeat 2 digits only for all others
    • 1908–15  1949–50  1980–81  2001–10  2012–16
    • during the period 1861–67; the 1846–48 conflict
  • For display, e.g., chapter or book titles, repeat all digits.
    • Chapter 1: 1840–1848
  • No en dash with from or between
    • from: use to or through. from 1861 to 1867
    • between: use and. between 1796 and 1920
First year Second year Repeat
Any Century changes All  1996–2016
Ends in 00 Ends in 00 All  1900–2000
Ends in 00 Ends in 01–09 All  2000–2009
Ends in 00 Ends in 10–99 All   1900–1924   2000–2010
Ends in 01–09 Ends in 00 All   1808–1900
Ends in 01–09 Ends in 01–09 1 digit only (CMS pref.)   1901–2  2003–9
or All (if publisher prefers)   1901–1902  2003–2009
Ends in 01–09 Ends in 10–99 2 digits only  1901–10  2005–17
Ends in 10–99 Ends in 00 All   1996–2000
Ends in 10–99 Ends in 01–09 All   1996–2001
Ends in 10–99 Ends in 10–99 (same century)
 2 digits only   1910–14  1998–99  2015–20

Source: CMS 9.59–63. (See also 6.78 “En Dash as To” for other types of spans such as times and dates.)

AP Style

  • AP does not publish official rules regarding number ranges, but a search of their “Ask the Editor” section reveals the following:
  • They use a hyphen instead of an en dash.
  • Repeating two digits for short year spans is preferred, but repeating all digits is still acceptable.
    • 2006-15 preferred, or 2006-2015 acceptable, or “from 2006 to 2015.”
  • Beyond a range of about 10 years, repeating all digits is preferred.
  • When asked about page numbers, AP usually responds vaguely, but seems to favor repeating all digits: “page 216-218 is probably clearer.”

Source: apstylebook.com