The following charts may be useful when using older crochet patterns that specify weights and linear measurements in the old Imperial system. Only the figures in red are more precise.
WEIGHT
| IMPERIAL | METRIC |
| 1/2oz | 14g |
| 1oz | 28.35g |
| 4ozs | 113.5g |
| 8ozs | 227g |
| 1Lb | 453.6g |
LENGTH
| IMPERIAL | METRIC |
| 1/16″ | 1.5mm |
| 1/8″ | 3mm |
| 1/4″ | 6mm |
| 1/2″ | 1.25cm |
| 3/4″ | 1.9cm |
| 1″ | 2.54cm |
| 3″ | 7.5cm |
| 6″ | 15cm |
| 9″ | 23cm |
| 1ft | 30.48cm |
| 24″ | 61cm |
| 36″ | 91.5cm |
YARDAGE
While balls of thread and yarn are sold by weight, the yardage/meterage is important when determining how many balls to buy – as different yarns with the same weight has a different length of thread. Most patterns will indicate either the yardage or meterage needed, and often this may need to be converted. How do you convert yarn?
Yards to meters: Multiply by .9144. Example – A ball has 300 yards = (300 x .9144) 274.32 metres
Meters to yards: Multiply by 1.0936. Example – A ball has 350 metres = (350 x 1.0936) 382.76 yards.
Below are some approximate equivalents for common yardage.
| YARDS | METRES |
| 100 | 91.44 |
| 200 | 182.88 |
| 300 | 274.32 |
| 400 | 365.76 |
| 500 | 457.20 |
| 1000 | 914.4 |