A yard is defined as 0.9144 metres
Since the 1959 international yard and pound agreement the yard has been exactly 0.9144 metres, which makes a metre 1.0936133… yards. The two units are close enough that they are often treated as interchangeable in casual speech, and far enough apart that a 100 m sprint is 109.36 yards — nearly ten yards longer than a 100-yard dash.
meters = yards × 0.9144 | yards = meters ÷ 0.9144
Rough conversion in your head
Knock ten percent off yards to get metres: 100 yd → 90 m, against a true 91.4. Add ten percent to metres to get yards: 400 m → 440 yd, against a true 437.4. Both land within a couple of percent, which is fine for fabric, football fields and golf course markers; the calculator gives the exact figure when it matters.