When it comes to the Canadian Revenue Agency, always go to the source. Wikipedia is a good source for certain information but not as reliable.
Currently 50.00% of realized capital gains are taxed in Canada at an individual’s tax rate. (ie $100 CG with 43% tax rate will attract $21.50 of tax.) Some exceptions apply, such as selling one’s primary residence which may be exempt from taxation.
For example, if your capital gains (profit) is $100, you’re only taxed on $50 at your marginal tax rate. That is, if you were in the top tax bracket you’d be taxed at approx 43%. Formula for this example using the top tax bracket would be as follows:
(Capital gain x 50.00%) x marginal tax rate = capital gain tax
= ($100 x 50.00%) x 43%
= $50 x 43%
In this example your capital gains tax on $100 is $21.50, leaving you with $78.50.
The formula is the same for capital losses and these can be carried forward indefinitely to offset future years’ capital gains; capital losses not used in the current year can also be carried back to the previous three tax years to offset capital gains tax paid in those years.
Unrealized capital gains are not taxed.
Source: Capital gains tax - Wikipedia