<P> The official playing field in Canadian football is larger than the American, and similar to American fields prior to 1912 . The Canadian field of play is 110 by 65 yards (101 by 59.4 m), rather than 100 by 53 ⁄ yards (91.4 by 48.8 m) as in American football . The end zones in Canadian football are 10 yards deeper than American football end zones as the CFL uses 20 - yard (18.3 m) end zones . Prior to 1986, however, the end zones were 25 yards, with Vancouver's BC Place the first to use the 20 yard - long end zone in 1983 . However, beginning in 2016, the new home of the CFL's Toronto Argonauts, BMO Field, utilizes an 18 - yard - long end zone . Including the end zones, the Canadian field is almost 34% larger than the American field (87,750 square feet (8,152 m) for the Canadian field vs 57,600 square feet (5,350 m) for the American field). Occasionally, however, the Canadian field will have its end zone truncated at the corners so that the field fits in the infield of a running track . The only example in the CFL is the Percival Molson Memorial Stadium, home of the Montreal Alouettes . The goalposts for kicking are placed at the goal line in Canadian football and the end line in the American game . In Canadian rules, the distance between the sideline and hash marks is 24 yards (21.9 m); in American amateur rules, at the high school level, the distance is 17 yards 2 feet 4 inches (16.3 m), virtually sectioning the field into three equal columns . The hash marks are closer together at the American college level, where they are 20 yards (18.3 m) from the sideline, and in the NFL, where they are 23 yd 1 ft 9 in (21.6 m) from the sideline and the distance between them is the same as that between the goalposts . </P> <P> Because of the larger field, many American football venues are generally unfit for the Canadian game . While there are several American stadia which could accommodate the extra ​ 17 ⁄ feet (nearly 6 yards (5.5 m) per side in width (multi-purpose stadiums, baseball parks converted for football, and some soccer - specific stadiums are particularly good fits), most American stadia would lose between fifteen and eighteen rows of seating in each end zone because the field is 15 yards (13.7 m) longer on each end . In many smaller venues, this would be the entire end zone section, losing seating for at least 3,000 spectators . During the CFL's failed expansion to U.S. cities, Canadian football was either played on fields designed to accommodate both American football and baseball (such as the Baltimore Stallions playing at Memorial Stadium), or in some cases, on a field designed for American football (for instance, the Memphis Mad Dogs and the Birmingham Barracudas of the CFL, playing in the Liberty Bowl and at Legion Field, respectively, played the Canadian game on modified American - sized fields because of the inability of the stadia to adapt to the larger field). The Alamodome, originally built as a multi-purpose dome, proved to best accommodate both Canadian football (the CFL's San Antonio Texans) and American football (Alamo Bowl, Dallas Cowboys training camp, the New Orleans Saints after Hurricane Katrina, the NFLPA Game, the U.S. Army All - American Bowl and the UTSA Roadrunners), although Canadian football is no longer played there . Similarly, Hornet Stadium fairly easily adapted to both the Canadian and American game, as it was built with a running track in which the Canadian field fits with only some cuts to the corners . Hornet Stadium hosts California State University, Sacramento (more often known as Sacramento State), hosted the Sacramento Surge and Sacramento Mountain Lions in American football and hosted the Sacramento Gold Miners in Canadian football . </P> <P> American teams use eleven players, while Canadian teams have twelve players on the field per side . Both games have the same number of offensive players required at the line of scrimmage, so the twelfth player in the Canadian game plays a backfield position on offence, whereas this is usually a defensive back on defence . </P> <P> Because of this, position designations of the various offensive and defensive lines vary . For example, there is no tight end in most formations in Canadian football (this position was phased out in 1980 in the Canadian game). The typical offensive arrangement in Canadian football is for there to be two slotbacks instead of the American tight end, while on the defensive end of the ball, two defensive halfbacks are used instead of one strong safety in the American game . </P>

How many players are on the field in the cfl