Each airline has its own baggage policy, and the list of links below will help you view the actual baggage allowances. Note that the free allowance will differ depending on where you are flying from and your destination. For example, Air Canada and Westjet Vacations both allow one normal sized piece of luggage checked for free, but you will pay for each additional checked piece.
Some US carriers charge for each and every checked piece, and what seemed like a great deal turns out to be more than you expected. If you are flying on a charter flight to a sunny destination, the normal baggage allowance is 2 pieces totaling no more than 20kg in total. One normal sized suitcase, provided it is not packed with heavy items, will weigh approximately this amount.
When traveling to Europe or Asia from Canada, most scheduled airlines allow two pieces totaling no more than 32 kg per piece, but this varies, as some charter flight operators maintain the 20kg total allowance. If you are planning to take a flight within Europe or Asia, be careful. You are allowed much more on the transatlantic and transpacific portion, but within Europe and Asia, the free allowance is 20kg total. There are many travelers who have ran into surprise charges.
Excess baggage charges are punitive. Some charge $5 per kg over, others up to $40 per kg, and others have odd tariffs such as a percentage of the full economy fare per unit of weight in excess.
Bottom line, if you are traveling with more than a normal sized suitcase, with normal weight of clothes, you need to check the baggage restrictions carefully.
The size of your baggage also matters, not the weight. Many airlines have a size principle where the length, depth, and height cannot exceed a specified amount, or a total amount of all three. Again, if you have anything other than a normal sized suitcase, it’s important to check this in advance. Some airlines are very stringent with this, and you will see people re-packing on the floor at checkin, or throwing articles out to meet the weight and size restrictions.
Here are quick links to the baggage allowance and restrictions pages for each airline:
Full list of airline baggage allowance: