Source: Elections Canada


Redistribution describes both the allocation of seats in the House of Commons to the provinces and the procedure for drawing specific constituency boundaries within the provinces. This occurs every 10 years, after a census in a year ending in “1,” such as 2011 — known as a “decennial census.”

One of the central principles of liberal democracy is political equality, the idea that all citizens should be equal. When it comes to representation in Canada’s House of Commons, this principle implies that citizens should have roughly equal “weight” in the House, meaning that Members of Parliament (MPs) should represent districts that are reasonably close in size in population. Complicating this is the fact that Canadians move frequently, both within and between provinces and territories. Furthermore, population growth through births and immigration does not occur at the same rate in all parts of the country. Consequently, every 10 years, the allocation of seats among provinces and territories is calculated using a formula established by Parliament. Within each province, independent boundary commissions draw the electoral boundaries for constituencies. The new boundaries go into effect one year after the governor general has proclaimed them.

Although at first glance, this would seem to be a straightforward mathematical exercise, the principle of political equality exists alongside the fact that Canada is a federal state and the idea that effective representation also requires the recognition of distinct communities. Balancing these principles is at the heart of the redistribution process. (See also Electoral Systems; Elections.)

This map references the number of federal electoral districts, or "ridings," in each province and territory. There are 338 districts in total, representing as many seats in the House of Commons.


Canada has gone through many different formulas for allocating seats among the provinces and territories. For the first few decades after the Second World War, the size of the House of Commons was capped, meaning that if one province gained seats, others would lose seats. However, when Newfoundland and Labrador joined Confederation in 1949, the cap was increased from 262 seats to 255. Also, in 1951, an amendment was passed that prevented the provinces from rapidly losing seats due to population decline.

After the 1971 census, Parliament decided to let the House of Commons grow, but it became clear after the 1981 census that the formula in the Representation Act (1974) would result in a House of Commons that would grow too quickly. The Representation Act (1985) therefore adopted a simpler set of rules, which produced a House of 295 seats for the 1988 and 1993 elections, 301 seats in 1997 and 2000, and 308 seats from 2004 to 2011.

Although this formula allowed for slow growth to the House of Commons, there were increasing disparities in representation between provinces over time. The fast growing provinces of Ontario, Alberta and British Columbia saw their representation in the House of Commons grow much more slowly than their population growth. In 2011, Parliament passed the Fair Representation Act, which established a new representation formula and resulted in a House of Commons with 338 members, based on the 2011 census.

Representation Formula

The current formula for allocating seats in the House of Commons follows four steps.

1. Initial Allocation

The formula for redistribution starts with the electoral quotient, which represents the starting number of people that each Member of Parliament should represent. In 2011, this number was legislated as 111,166. (After the 2021 decennial census, this will increase by the average population growth of the provinces.) Every province’s population is divided by the quotient, and any remaining fraction is rounded up. (Note: the territories are not included at this stage.) This gives each province its starting number of MPs. For example, Québec’s population in 2011 was 7,903,001. Divided by the quotient, this gives 71.09, which rounded up to 72 represents Québec’s starting allocation of MPs.

2. Minimum Seat Guarantees

This first allocation is then adjusted by applying what is known as the "Senate floor" rule and a special grandfather clause introduced in the 1985 Representation Act. The Senate floor has been in effect since 1915, and guarantees that no province will have fewer seats in the House of Commons than it has in the Senate. On the basis of the 2011 census, for example, Nova Scotia, New Brunswick, Prince Edward Island and Newfoundland and Labrador are entitled to fewer seats in the House than they have in the Senate. The grandfather clause provides that at future redistributions no province is allocated fewer seats than it had at the time the 1985 Act came into force. On the basis of the 2011 census, this rule protects seven provinces, including those protected by the "Senate floor." Québec’s representation went from 72 to 75 seats because of the application of this clause in 2011.

3. Representation Rule

This revised allocation is altered once more based on the “representation rule.” Introduced in 2011, the representation rule applies only to provinces with populations that were overrepresented at the end of the previous redistribution period. If those provinces become underrepresented after the application of the Senate floor and grandfather clauses, they receive additional seats to bring their representation in line with their share of the population. After the 2011 census, giving 75 seats to Québec would have meant that Québec would have only had 22.4 per cent of the seats in the House of Commons, less than their 23.2 per cent share of the population. Consequently, this rule meant that Québec received three additional seats, bringing its seat total to 78 and its share of national seats in line with its share of the population. In 2011, Québec was the only province that qualified under this rule.

4. Territorial Seats

These three steps determine the representation of each province in the House of Commons. After this, Northwest Territories, Nunavut and Yukon are each given one seat. By the application of these rules on the basis of the 2011 census, any House of Commons elected after April 2014 will have 338 seats. This enlarged House of Commons allowed for substantially increased representation for British Columbia, Alberta and Ontario, thus reducing — although certainly not eliminating — some of the inequities in representation between provinces.

Electoral District Boundaries

The very different and sensitive process of drawing individual constituency boundaries within a provincial allocation has been governed since 1964 by the Electoral Boundaries Readjustment Act (repealed and re-enacted with important changes in 1995 and amended several times since). The original Act established the practice of having constituency boundaries determined by independent boundary commissions in each province. However, each commission is now chaired by a judge, designated by the chief justice of the province, and has two other members appointed by the Speaker of the House of Commons from among people who have applied for the job or "from among such persons as the Speaker deems suitable."

Population remains the basic principle determining constituency boundaries. Each commission proceeds by dividing the total provincial population by the allocation of seats to produce a provincial electoral quota. The commissions are then to "proceed on the basis that the population of each electoral district in the province [...] shall, as closely as is reasonably possible, correspond to the electoral quota for the province." Although a commission may depart from a very strict application of this rule, none could recommend an electoral district whose population varied from the provincial electoral quota by more than 25 per cent either way (except in very special cases, such as rural or geographically isolated areas, or the far north, where the variance can go below 25 per cent under the provincial quota). The Act instructs commissions to consider "community of interest," “community of identity” and historical constituency boundaries in drawing the electoral map. As well, the Act instructs the commissions to maintain a “manageable geographic size” for sparsely populated districts.

Once the commissions have completed their work and issued their reports, MPs have an opportunity to file written objections to any of the boundaries or constituency names, providing they are signed by at least 10 MPs. Such objections are then sent back to the commission, which may or may not amend the report. Once the MPs’ objections have been considered, the commission can issue a final report. These final reports form the basis of a representation order, which is drafted by the Chief Electoral Officer, proclaimed by Cabinet in the Canada Gazette and then issued by the governor general.


Before 1964, the task of constituency boundary determination was undertaken by the government, without any reference to the House of Commons other than a bill which members were required to accept or reject. After 1903, constituency boundaries were determined by a parliamentary committee on which the government ordinarily had a majority, thus still getting its own way. These arrangements frequently resulted in outright gerrymandering (the deliberate manipulation of constituency boundaries to give the maximum partisan advantage to one party). Despite continuing argument about the most appropriate way to carry out this work, which is essential to a functioning democracy, the rules now in place at the federal level are a vast improvement on the past.