Representation in the House of Commons of Canada


"The right to vote and the right to be a candidate for election to the House of Commons
are necessary but not sufficient conditions to ensure that the electoral law promotes
both the equality of the vote and effective representation. How we assign Commons
seats to provinces and draw the constituency boundaries within provinces can
also affect the degree to which we realize these two objectives."

Royal Commission on Electoral Reform and Party Financing, 1991: 123

Several principles underlie Canada's system of parliamentary representation. The first of these is territorial representation, meaning that each elector is represented in the House of Commons on the basis of a geographical division, called the electoral district or constituency or riding. On a countrywide basis and within each constituency, the democratic goal of the electoral system is embodied in a second principle, that of "one elector ‑ one vote," which is set out in the Canada Elections Act. The application of this principle was clarified in a 1991 decision of the Supreme Court of Canada, which held that the right to vote as guaranteed by the Canadian Charter of Rights and Freedoms does not establish absolute equality of voting power but a right of "effective representation." It is on the basis of these two principles that electoral districts are drawn.

This publication has been prepared to shed some light on two fundamental but little-known aspects of the federal electoral system, namely:

  • the principle of representation in the House of Commons, in other words, how the seats in the House of Commons are divided among the 10 provinces and three territories;

    and, secondly,

  • how the electoral district boundaries are determined and periodically readjusted to reflect changing representation in the House of Commons and population movements from one region to another, as well as within each region.

This is not a comprehensive account of these topics but rather an overview, which it is hoped will serve to stimulate further interest in and study of Canada's electoral system.


One of the crucial questions faced by the Fathers of Confederation in 1867 was how to ensure equal representation in the House of Commons of Canada, while at the same time guaranteeing that each region of the country had a fair say in the daily workings of the new federation. They adopted the basic idea of "representation by population," by virtue of which each province was allotted a number of seats that directly corresponded to its proportion of the total population in relation to Quebec's. They then designed a formula for distributing the number of seats in the House of Commons among the provinces based on this idea.

From the start, however, they recognized the geographic, cultural, political and demographic diversity of the new provinces, as well as population size and rural and urban characteristics. As more provinces entered Confederation and as some regions grew and developed more than others, the diversity became more pronounced and a certain degree of compromise had to be built into the formula.

Many observers have commented that the history of Canada itself is one of compromises. Certainly, the question of provincial representation in the House of Commons is a case in point. Yet in spite of this, it is fair to say that even today "representation by population" remains at the root of the electoral system in Canada, as in many other countries.

The following pages briefly describe the evolution of the representation formula. This description is followed by an explanation of the present formula, how it is applied to determine the number of seats in the House of Commons, and how these are then divided among the provinces and territories.

Representation Since 1867 – Number of Seats
Year Canada Ont. Que. N.S. N.B. Man. B.C. P.E.I. Sask. Alta. N.W.T Y.T.
1867 181 82 65 19 15
1871 185 82 65 19 15 4
1872 200 88 65 21 16 4 6
1873 206 88 65 21 16 4 6 6
1882 211 92 65 21 16 5 6 6
1887 215 92 65 21 16 5 6 6 4
1892 213 92 65 20 14 7 6 5 4
1903 214 86 65 18 13 10 7 4 10 1
1907 221 86 65 18 13 10 7 4 10 7 1
1914 234 82 65 16 11 15 13 3 16 12 1
1915 235 82 65 16 11 15 13 4 16 12 1
1924 245 82 65 14 11 17 14 4 21 16 1
1933 245 82 65 12 10 17 16 4 21 17 1
1947 255 83 73 13 10 16 18 4 20 17 1
1949 262 83 73 13 10 16 18 4 20 17 1 7
1952 265 85 75 12 10 14 22 4 17 17 2 7
1966 264 88 74 11 10 13 23 4 13 19 2 7
1976 282 95 75 11 10 14 28 4 14 21 3 7
1987 295 99 75 11 10 14 32 4 14 26 3 7
1996 301 103 75 11 10 14 34 4 14 26 3 7
2003 308 106 75 11 10 14 36 4 14 28 3 7
2013** 338 121 78 11 10 14 42 4 14 34 3 7

*Nunavut became a territory separated officially from the Northwest Territories on April 1, 1999.
**Projected date of proclamation of the representation order.

History of the Formula

Confederation to 1915

At Confederation in 1867, the British North America Act, 1867 (renamed in 1982 the Constitution Act, 1867) established a parliament composed of two houses. The upper house, or Senate, was to consist of 72 non‑elected members, or 24 representing each of the three regions ‑ Quebec, Ontario and the Maritimes. The lower house, or House of Commons, elected by eligible voters, was to comprise 181 members representing the four founding provinces ‑ 82 for Ontario, 65 for Quebec, 19 for Nova Scotia and 15 for New Brunswick.

In order that each province's representation in the House of Commons continued to reflect its population, section 51 of the Act stated that the number of seats allocated to each province would be recalculated after each 10-year (decennial) census, starting with the 1871 Census. The total number of seats was to be calculated by dividing the population of each province by a fixed number, referred to as the "electoral quota" or "quotient." This quota was to be obtained by dividing the population of the province of Quebec by 65, the number of seats guaranteed for Quebec by the Constitution in the House of Commons.

This simple formula was to be applied with only one exception, "the one-twentieth rule," under which no province could lose seats in a redistribution unless its share of the national population had decreased by at least five percent (one twentieth) between the last two censuses.

1915 – The senatorial clause

In 1915, the first change was made to the original representation formula, by the adoption of the "senatorial clause." Still in effect today, this clause states that a province cannot have fewer seats in the House of Commons than it does in the Senate. In 1915, it had the immediate effect of guaranteeing four seats to the province of Prince Edward Island, instead of the three it would otherwise have had. It has had four seats ever since.

1946 – Changing the formula

Changing political circumstances and relationships, however, led to the development of a new set of rules, adopted in 1946 when the British North America Act was amended. These new rules divided 255 seats among the provinces and territories based on their share of Canada's total population, rather than on the average population per electoral district in Quebec.

1951 – The 15 percent clause

Since the population of all provinces had not increased at the same rate, certain provinces lost seats. Because Nova Scotia, Manitoba and Saskatchewan were all to lose seats after the 1951 Census, the "15 percent clause" was adopted to prevent a too rapid loss of seats in some provinces. Under these rules, no province could lose more than 15 percent of the number of House of Commons seats to which it had been entitled at the last readjustment. The same three provinces, plus Quebec, however, all lost seats after the 1961 Census. These same four provinces, plus Newfoundland, would also have lost seats after the 1971 Census, so legislation was introduced to resolve this particular situation in 1974.

1974 – The "amalgam" formula

In 1974, concern over the continuing loss of seats by some provinces prompted Parliament to adopt the Representation Act, 1974, which, among other things, guaranteed that no province could lose seats.

In February 1974, the Standing Committee on Privileges and Elections established that:

  • The objective must be adequate and realistic representation of all Canadians bearing in mind the historic undertakings arising out of Confederation and its responsibilities. The allocation of seats (in the House of Commons) is at the very heart of the Confederation compromise.

A "compromise" was therefore proposed to deal with representation in the House of Commons. The new formula, the third in our history, was more complicated than earlier ones. As in the pre-1946 rules, Quebec was used as the basis for calculations, but there were three differences. First, Quebec would henceforth be entitled to 75 seats instead of 65. Second, the number of seats assigned to Quebec was to grow by four at each subsequent readjustment in such a manner as to slow down the growth in the average population of an electoral district. Third, three categories of provinces were created: large provinces, those having a population of more than 2.5 million, intermediate provinces, namely, those with populations between 1.5 million and 2.5 million, and small provinces, with populations under 1.5 million. Only the large provinces were to be allocated seats in strict proportion to Quebec; separate and more favourable rules were to apply to the small and intermediate provinces.

The amalgam formula was applied once, leading to the establishment of 282 seats in 1976.

1985 – The Representation Act

Following the 1981 Census, calculations revealed that the amalgam formula would result in a substantial increase in the number of seats in the House of Commons both immediately and after subsequent censuses (369 seats were projected after 2001). In passing the Representation Act, 1985, Parliament changed the formula and also brought into effect a new "grandfather clause" that guaranteed each province no fewer seats than it had in 1976 or during the 33rd Parliament (that is, in 1985).

The revised formula for calculating seats involved several steps: Starting with the 282 seats in the House of Commons in 1985, one seat was allocated to the Northwest Territories, one to the Yukon and one to Nunavut, leaving 279 seats. The total population of the 10 provinces was divided by 279 to obtain the "electoral quota" or "quotient." The initial number of seats for each province was calculated by dividing the total population of each province by the quotient. If the result left a remainder higher than 0.50, the number of seats was rounded up to the next whole number. Then the "senatorial clause" and "grandfather clause" were applied to obtain the final seat numbers.

The Present Formula

In 2011, the federal government introduced a bill to tackle the significant under-representation of fast-growing provinces, namely Ontario, British Columbia and Alberta, which the 1985 formula could not address. It also aimed to ensure that over-represented provinces would not become under-represented after applying the new formula. The Fair Representation Act, passed in December 2011, resulted in more seats for the three fastest-growing provinces as well as for Quebec, which would have otherwise become under-represented. The number of seats for slower-growing provinces was maintained. Ontario was allotted 15 additional seats, British Columbia and Alberta each gained 6 seats, and Quebec received 3 more seats.

The current representation formula involves the following steps:

1. Initial allocation of seats to the provinces

The population of a province is divided by the "electoral quotient" to provide the initial allocation of seats to that province. The electoral quotient for the 2012 redistribution process was set by law at 111,166, which is the estimated average population of the electoral districts in the provinces as at July 1, 2011.

For future redistributions, the electoral quotient will be adjusted using the average of the rates of provincial population growth since the previous redistribution.

2. Application of the special clauses

After the initial number of seats per province is obtained, adjustments are made to account for the "senatorial clause" and the "grandfather clause."

3. Application of the "representation rule"

The "representation rule" is applied to a province whose population was over-represented in the House of Commons at the completion of the last redistribution. If such a province would now be under-represented based on the calculations above, it will be given extra seats so that its share of House of Commons seats is proportional to its share of the population.

4. Calculation of House of Commons seats

Once the special clauses and representation rule are applied, the number of seats for each province has been determined. Three seats are then allocated to the territories – one for each of the Yukon, the Northwest Territories and Nunavut – to obtain the total number of House of Commons seats.

Provincial population ÷ Electoral quotient (111,166) = Initial provincial seat allocation

Application of the "senatorial clause" and "grandfather clause"

Application of the "representation rule"

Total provincial seats + One seat per territory = Total number of seats

The present formula for calculating representation in the House of Commons.