I think you can use SUMIF

e,g,

=SUMIF(A1:A10,">=33",B1:B10)

if 33 is in an imput cell, then

=SUMIF(A1:A10,">="&C1,B1:B10) where C1 is your input cell

if the formulas don't work, replace the commas ( , ) with semicolons ( ; )