Here is an approximation for E13:

= 1 - (B4+C8+C10)*1.005 / ((E14/1.15)-C6-C7)

Is that what you meant?

Hope this helps.

Pete

On Apr 27, 4:32*pm, Eric wrote:
Does anyone have any suggestions on how to separate the E13 from following
formula?
E14/1.15=C6+C7+ROUNDUP((B4+C8+C10)/(1-E13)/500,0)*2.5+(B4+C8+C10)/(1-E13)

E13=???
Thanks in advance for any suggestions
Eric