Right from the Canada Revenue Agency website.

Calculating your capital gain or loss
To calculate any capital gain or loss, you need to know the
following three amounts:
■ the proceeds of disposition;
■ the adjusted cost base (ACB); and
■ the outlays and expenses incurred to sell your property.
To calculate your capital gain or loss, subtract the total of
your property’s ACB, and any outlays and expenses
incurred to sell your property, from the proceeds of
disposition.
You have a capital gain when you sell, or are considered to
have sold, a capital property for more than the total of its
ACB and the outlays and expenses incurred to sell the
property.
Example
In 2007, Mario sold 400 shares of XYZ Public Corporation of
Canada for $6,500. He received the full proceeds at the time
of the sale and paid a commission of $60. The adjusted cost
base of the shares is $4,000. Mario calculates his capital gain
as follows:
Proceeds of disposition $ 6,500 A
Adjusted cost base $ 4,000 B
Outlays and expenses on
disposition (eg comission)
+
60
C
Line B plus line C = $ 4,060 – 4,060 D
Capital gain (line A minus line D) = $ 2,440 E
Because only 1/2 of the capital gain is taxable, Mario
completes Schedule 3 and reports $1,220 as his taxable
capital gain on line 127 on his return.