If I understood the table and calculation:

Create table as below (A1 to C8 in my example):

Column A are commission steps
Column B is %
Column C is combined commission

0 5.00% 0
2000 10.00% 100
5000 15.00% 400
10000 17.00% 1150
15000 20.00% 2000
20000 22.00% 3000
25000 25.00% 4100
35000 30.00% 6600

and use the follwing formula:

=VLOOKUP(G14,$A$1:$C$8,3,1)+(G14-VLOOKUP(G14,$A$1:$C$8,1,1))*(VLOOKUP(G14,$A$1:$C$8 ,2,1))

HTH
" wrote:

Hi,

This is our commission structure...

£'s Percentage % £ per bracket Combined Commission
0 - 2,000 5 100 100
2,001 - 5,000 10 300 400
5,001 - 10,000 15 750 1,150
10,001 -15,000 17 850 2,000
15,001 - 20,000 20 1,000 3,000
20,001 - 25,000 22 1,100 4,100
25,001 - 35,000 25 2,500 6,600
35,000+ 30

I tried
=IF(G14<2000,G14*0.05,IF(G14<5000,100+(G14-2000)*0.1,IF(G14<10000,400+(G14-5000)*0.15,IF(G14<15000,1150+(G14-10000)*0.17
etc etc, but I can't fit it all in AND it's a bit big and cumbersome.

I have a feeling that it might be an array that makes this work?

Thanks,