ROM --- Is it -50 % to 50 % or -25% to +75%

Hi All,

Slightly confused with ROM.
Please let me know the percentage bracket for ROM.

Is it

a. -50 to +50

b. -25 to +75

Appreciate your time.



anmol2701's picture

It's -25 to +75% according to PMBOK 5.0


-50 to +50% according to PMBOK 4.0


So, if question is asked in today's date answer would be first one.

thanks Anmol.



ROM, as the name suggest its “Rough”. Although in PMBOK you will see some min-max range given, but in reality and in the PMP exam they can vary further. Rough is anything “Rough” and it cannot have a fix range.

Saket, PMP

admin's picture

here is the exact text from PMBOKv5

Cost estimates should be reviewed and refined during the course of the project to reflect additional detail as it becomes available and assumptions are tested. The accuracy of a project estimate will increase as the project progresses through the project life cycle. For example, a project in the initiation phase may have a rough order of magnitude (ROM) estimate in the range of −25% to +75%.