The Call of Duty: Modern Warfare campaign is usually about 5 to 6 hours for a normal playthrough. Some players finish it in around 4–5 hours , while a slower run can take 7–8 hours.

What affects the time

  • Difficulty : harder settings can add time.
  • Play style : rushing missions is faster than exploring or replaying sections.
  • Version : the 2019 Modern Warfare reboot is the one these estimates refer to.

Quick answer for your post

Version| Typical campaign length
---|---
Modern Warfare (2019)| 5–6 hours
Fast run| 4–5 hours
Slower run| 7–8 hours

If you want, I can also rewrite this into a short forum-style reply with a more casual tone.