How do you convert yards to meters?
Multiply by 0.9144. That's exact – the yard has been defined as 0.9144 m since 1959 – so 100 yards is 91.44 m, a shade short of a 100 m track.
In your head, take off a tenth: 100 yards becomes 90 m, about 1.6% low. Near enough for pacing out a garden, not for anything that has to fit.
Definition of a yard
A yard (yd) is 3 feet or 36 inches. It is an American and British unit, and Britain still gives short road distances in yards.
The yard is traditionally said to be the distance from the nose of King Henry I to the thumb of his outstretched arm, though that is a legend and not a record. Since the international yard and pound agreement of 1959 it has been exactly 0.9144 meters.
American football fields are 100 yards between the goal lines, with an end zone 10 yards deep at each end. In the US fabric is also sold by the yard, so you can still ask for three yards of velvet and be understood.
Definition of a meter
The meter belongs to the SI and the yard to the imperial and US customary systems. The meter is about 9.4% longer, at 1.0936 yards.
The meter is defined as the length of the path traveled by light in a vacuum during a specific time interval. It is currently defined as exactly 1/299,792,458th of the distance light travels in one second. This definition ensures that the meter is a constant and universally applicable unit of length.
The yard is defined as exactly 0.9144 meters, so it has no definition of its own any more – it is simply a fixed fraction of the meter. That has been so since the 1959 agreement; before that the British and American yards differed very slightly.