Cheat Sheets
PEC Wire Ampacity (THHN/THWN)
*Based on Philippine Electrical Code (PEC) for copper wires in a raceway/conduit.
| Size (mm² / AWG) | Max Ampacity | Max Breaker & Usage |
|---|---|---|
| 2.0 mm² (#14) | 25 Amps | 15A (Lighting Circuits) |
| 3.5 mm² (#12) | 30 Amps | 20A (Convenience Outlets) |
| 5.5 mm² (#10) | 40 Amps | 30A (A/C, Water Heaters) |
| 8.0 mm² (#8) | 55 Amps | 40A (Ranges, Subpanels) |
| 14.0 mm² (#6) | 75 Amps | 60A (Small House Main) |
| 22.0 mm² (#4) | 95 Amps | 80A / 90A (Standard Main) |
| 30.0 mm² (#2) | 130 Amps | 100A (Large House Main) |
PVC Pipe Nominal Sizes
| Inches (Imperial) | Millimeters (Metric) |
|---|---|
| 1/2" | 20 mm |
| 3/4" | 25 mm |
| 1" | 32 mm |
| 1 1/4" | 40 mm |
| 1 1/2" | 50 mm |
| 2" | 63 mm |
| 3" | 90 mm |
| 4" | 110 mm |
Nail Sizes (Penny to Inches)
| Penny Size (d) | Length (Inches) |
|---|---|
| 2d | 1" |
| 3d | 1 1/4" |
| 4d | 1 1/2" |
| 6d | 2" |
| 8d | 2 1/2" |
| 10d | 3" |
| 16d | 3 1/2" |
| 20d | 4" |
Lumber Board Foot
Lumber is often sold by the Board Foot (bd ft), which is a volume measurement representing a piece of wood 12" x 12" x 1".
(Thickness" × Width" × Length') ÷ 12
Example: A 2" x 4" x 10' piece of lumber.
(2 × 4 × 10) / 12 = 6.67 Board Feet