2 Measuring Systems
Measurement systems
The construction industry in Canada uses both the metric and the imperial systems of measurement. The architect’s or engineer’s plans and specifications dictate which system the tradesperson must use; therefore they must carry measuring tools for both systems.
Imperial system
The imperial system uses feet and inches and fractions of an inch. There are 12 inches to a foot and inches are divided into halves, quarters, eighths, and sixteenths.
Metric system
The base unit of length in the metric system is the meter. The meter is divided into 1000 units (millimeters). Measuring tapes are usually marked off in 10 millimeter units (centimeters). One hundred centimeters equals one meter.
Conversion Between Imperial and Metric
- 25.4 mm is equal to 1 inch
- 304.8 mm equals 1 foot
| Inches | Millimeters | Actual (mm) |
|---|---|---|
| 1 / 16 | 2 | 3.59 |
| 1 / 8 | 3 | 3.18 |
| 3 / 16 | 5 | 4.76 |
| 1 / 4 | 6 | 6.35 |
| 5 / 16 | 8 | 7.94 |
| 3 / 8 | 10 | 9.53 |
| 7 / 16 | 11 | 11.11 |
| 1 / 2 | 13 | 12.7 |
| 9 / 16 | 14 | 14.29 |
| 5 / 8 | 16 | 15.88 |
| 11 / 16 | 17 | 17.46 |
| 3 / 4 | 19 | 19.05 |
| 13 / 16 | 21 | 20.64 |
| 7 / 8 | 22 | 22.23 |
| 15/16 | 24 | 23.81 |
| 1 | 25 | 25.40 |