How are the commissions paid, in the purchase and sale of stocks, deducted in Canadian Tax returns?

If I pay $500.00 plus 25.00 commission for shares in a company and I sell them for $1000.00 plus $50.00 commission, what is the calculation that I make to show an accurate gain? I assume that I have cleared $425.00. Is there an easy spreadsheet formula that one can use?

see - Schedule 3 Capital Gains (or Losses) in 2007 from link below;

For stocks that you buy and then sell or sell first and buy back (short selling) this schedule outlines how the trades are accounted for. You simply fill in the columns for each trade. The information required is as follows:
Year of acquisition (2)
Proceeds of disposition (3)
Adjusted cost base (4)
Outlays and expenses (from dispositions) (5)
Gain (or loss) (column 2 minus columns 3 and 4)

The Adjusted Cost Base includes the purchase price of the stock plus commissions paid (column 4)

The Proceeds (column 3) is the sale proceeds before commissions. The sale commissions are captured under Outlays and Expenses (column 5)

In your example you would have $425 in capital gains which assuming no other gains or losses would be reported in Box 197. You would then take 50% of this amount and enter it in box 199 ($212.50) and this amount is transfered to line 127 under income and is reported as a net capital gain.

Therefore the commissions paid on the purchase and sale of stock reduces the capital gains reported. A $1 commission reduces capital gains by a dollar and this is then reported as $0.50 less income for purposes of calculating tax.

No, the commission is not tax deductible. However, the carrying costs (ie: safety-deposit box fees, MERs, interest expenses, custodial / accounting / management / investment counsel fees) of your non-registered portfolio are tax deductible.

The commissions are added to the ACB which lowers the capital gains paid on the non-reg. investment when you sell the stock.