Standard room door width – 24 – 30 – 36
How to Measure a Door? What is standard door width? : Standard Room Door Width 24 30 36
Quote from Article entitled How to Measure a Door? What is standard door width?:
If there is a discrepancy in the measurements, the final step will be to correct them. If the door is too wide, all you need to do is to mark the required dimensions and shave off the extra wood. If it is too narrow, more often than not the best solution is to make adjustments to the door frame on the wall.
The full version of the article can be found here.