I have been trying to work out what gross sales are needed in order to
generate a profit after tax of $1,000,000. i think i will need to use
something like Goal Seek or Solver but i don't have a formula set up so i
can't use them yet.

Currently, this is what the financial data looks like: (assumptions in
brackets)
Gross Sales $2,105,500.00
Net Sales $2,085,500.00 (Gross sales - 3%)

MM&G $417,100.00 (20% of Net Sales)
Labour $325,000.00
Materials $600,000.00
Variable Overheads $277,500.00 (30% of Labour + Overheads)
Fixed Overheads $70,000.00

Cost of Goods Sold $1,272,500.00 (Labour+Materials+Overheads)

Gross Profit $813,000.00 (Net Sales - Cost of Goods Sold)
Profit Before Tax $395,900.00 (Gross Profit - MM&G)
Tax $138,565.00 (35% of Profit Before Tax)

Profit $257,335.00 (This is the figure i hope to reach
$1,000,000 on by changing the gross sales which has a flow-on effect with
some of the other figures).