Mass is the amount of material contained within a defined volume. This table provides some of the most often used conversion factors between units.
Standard units = Kilogram (kg)
| | ounce | pound | ton | gram | kilogram | slug | u† |
| 1 oz = | 1 | 6.250 * 10-2 | 3.125 * 10-5 | 28.35 | 2.835 * 10-2 | 1.942 * 10-3 | 1.708 * 1025 |
| 1 lb = | 16 | 1 | 0.0005 | 453.6 | 0.4536 | 3.108 * 10-2 | 2.732 * 1026 |
| 1 ton = | 3.200 * 104 | 2000 | 1 | 9.072x105 | 907.2
| 62.16 | 5.465 * 1029 |
| 1 g = | 3.527 * 10-2 | 2.205 * 10-3 | 1.102 * 10-6 | 1 | 0.001 | 6.852 * 10-5 | 6.024 * 1023 |
| 1 kg = | 35.27 | 2.205 | 1.102 * 10-3 | 1000 | 1 | 6.852 * 10-2 | 6.024 * 1026 |
| 1 slug = | 514.8 | 32.17 | 1.609 * 10-2 | 1.459 * 104 | 14.59 | 1 | 8.789 * 1027 |
| 1 u = | 5.855 * 10-26 | 3.660 * 10-27 | 1.829 * 10-30 | 1.660 * 10-24 | 1.660 * 10-27 | 1.137 * 10-28 | 1 |
† = atomic mass unit