The Fitment Factor is the most discussed topic in the 8th Pay Commission. The government uses this specific multiplier on the current Basic Pay to fix the new basic salary.
For example, an employee currently gets a Basic Pay of Rs 44,900. The panel might use an estimated 2.1 Fitment Factor.
The calculation (Rs 44,900 x 2.1) brings the new Basic Pay to Rs 94,290.
However, the government has not officially announced this 2.1 Fitment Factor yet. The 8th Pay Commission will recommend the actual Fitment Factor, and the central government will take the final call.