Easy Calculator OROP arr up to Dec 22:-
OROP2 Basic pension(-)OROP1basic pension as per tables=Say XYZ.
XYZ×52.26=Total arr.
Total arr÷4=1st installment.
If you are also getting disability pension then (for 50% disabilty):-
XYZ+(30%ofXYZ)=say
ABC.
ABC×52.26=Total arr incl disability.
""52.26""is megic multiplication factor whch incl all your DA/DR fm 01jul19 till dec22.