Appendix B — Imperial Conversion
Imperial Conversions of Metric Values
Imperial conversions may be determined using the factors listed below.
| to Convert | to | Multiply by |
|---|---|---|
| °C | °F | 1.8 and add 32 |
| g | oz | 0.0353 |
| g | lb | 0.0022 |
| kg | lb | 2.2046 |
| kg/m² | lb/ft² | 0.20481 |
| kPa | lb/in² | 0.14503 |
| kPa | lb/ft² | 20.885 |
| L | gal (Imp) | 0.21997 |
| L | gal (US) | 0.26417 |
| L/m² | gal/ft² (Imp) | 0.02044 |
| L/s* | gal/min (Imp) | 13.198 |
| L/s* | gal/min (US) | 15.850 |
| L/s** | ft³/min | 2.1189 |
| L/s·m | cfm/ft | 0.64584 |
| L/s·m² | cfm/ft² | 0.19685 |
| lx | ft-candle | 0.09290 |
| mm | in | 0.03937 |
| m | ft | 3.2808 |
| m² | ft² | 10.764 |
| m³ | ft³ | 35.315 |
| m³/h | ft³/min | 0.58857 |
| m/s | ft/min | 196.85 |
| MJ | Btu | 947.82 |
| m²·°C/W (RSI) | ft²·h·°F/Btu (R) | 5.6785 |
| N | lbf | 0.22481 |
| ng/Pa·s·m² | perms | 0.01741 |
| W | Btu/h | 3.4122 |
| Column 1 | 2 | 3 |
Notes:
* liquid volume flowrate
** air volume flowrate
SI Units and Their Multiples
The SI prefixes used to form names and symbols of decimal multiples and sub-multiples of SI units are:
| Prefix | Symbol | Magnitude | Factor |
|---|---|---|---|
| exa | E | 1,000,000,000,000,000,000 | 1018 |
| peta | P | 1,000,000,000,000,000 | 1015 |
| tera | T | 1,000,000,000,000 | 1012 |
| giga[1] | G | 1,000,000,000 | 109 |
| mega[1] | M | 1,000,000 | 106 |
| kilo[1] | k | 1,000 | 103 |
| hecto[2] | h | 100 | 102 |
| deca[2] | da | 10 | 101 |
| deci[2] | d | 0.1 | 10−1 |
| centi[2] | c | 0.01 | 10−2 |
| milli[1] | m | 0.001 | 10−3 |
| micro[1] | µ | 0.000001 | 10−6 |
| nano[1] | n | 0.000000001 | 10−9 |
| pico | p | 0.000000000001 | 10−12 |
| femto | f | 0.000000000000001 | 10−15 |
| atto | a | 0.000000000000000001 | 10−18 |
| Column 1 | 2 | 3 | 4 |
Notes:
- most frequently used
- avoid if possible
Updated: September 14, 2026
Published: May 22, 2026