On Sunday, June 2, 2013 1:21:54 PM UTC-7, Ardy wrote:
The result I am after is in one cell, I need the formula to
enter 150.00 if the calculation result is less ten 150.00
[=IF((B5*M5)<150,150,(B5*M5))] and enter 500.00 if the calculation
is greater than 500.00[=IF((B4*M4)500.01,500,(B4*M4))]

so the two IF will be in the same cell.

The above shows 2 different calculations: the first referencing row 5 and the second referencing row 4. So what does "the" calculation mean?

I'm guessing that the intent is to refer to the same row; that is, the same calculation is compared with both 150 and 500. If that's right -- while it's possible to write nested IF's -- it's more straightforward to use this, in my opinion:
=MAX(150,MIN(B4*M4,500))