You could set calculation to Manual while entering the data and recalculate with F9.
10 minutes seems a bit long, but we don't know your formulas. Especially VLOOKUP and HLOOKUP are very sensitive for the 4th
argument.

For many tips about performance, especially lookups, check he
www.decisionmodels.com

And/or post your formulas (in this thread)

--
Kind regards,

Niek Otten

"Siva" wrote in message ...
I have a file, that is +- 200MB in size, and has +- 150 worksheets with 700
lines of formulaes in each worksheet.

Problem is that when I update the one sheet where the lookup is, it takes
about 10min to do the calculation.

I am also running a PIV 3Ghz HT with 1gig RAM.

How can I get Excel to perform faster?