The density, or more precisely, the volumetric mass density of radium is 5000 kg/m³. This means that the mass of 1 m³ radium is 5000 kg.
The weight (on earth) of 1 m³ radium is 49050 N or 49,05 kN.
Conversion Chart Metric System:
| Kilogram per cubic meter | 5000 | kg/m³ |
| Tonne per cubic meter | 5 | t/m³ |
| Gram per cubic meter | 5000000 | g/m³ |
| Milligram per cubic meter | 5000000000 | mg/m³ |
| Kilogram per cubic centimeter | 0,005 | kg/cm³ |
| Gram per cubic centimeter | 5 | g/cm³ |
| Milligram per cubic centimeter | 5000 | mg/cm³ |
| Kilogram per litre | 5 | kg/L |
| Gram per litre | 5000 | g/L |
| Milligram per litre | 5000000 | mg/L |
| Kilogram per millilitre | 0,005 | kg/mL |
| Gram per millilitre | 5 | g/mL |
| Milligram per millilitre | 5000 | mg/mL |
Conversion Chart British and U.S.:
| Pound per cubic yard | 8430 | lb/yd³ |
| Pound per cubic foot | 312,15 | lb/ft³ |
| Pound per cubic inch | 0,18065 | lb/in³ |
| Pound per U.S. gallon | 41,725 | lb/gal |
| Pound per British gallon | 50,1 | |
| Pound per U.S. bushel | 388,45 | |
| Ounce per cubic yard | 134850 | oz/yd³ |
| Ounce per cubic foot | 4994 | oz/ft³ |
| Ounce per cubic inch | 2,89 | oz/in³ |
| Ounce per U.S. gallon | 667,5 | oz/gal |
| Ounce per British gallon | 802 | |
| Ounce per U.S. bushel | 6215 |
British Gravitational and English Engineering Units:
| Slug per cubic yard | 261,95 | slug/yd³ |
| Slug per cubic foot | 9,7 | slug/ft³ |
| Slug per cubic inch | 0,005615 | slug/in³ |