The density, or more precisely, the volumetric mass density of niobium is 8570 kg/m³. This means that the mass of 1 m³ niobium is 8570 kg.
The weight (on earth) of 1 m³ niobium is 84071,7 N or 84,0717 kN.
Conversion Chart Metric System:
| Kilogram per cubic meter | 8570 | kg/m³ |
| Tonne per cubic meter | 8,57 | t/m³ |
| Gram per cubic meter | 8570000 | g/m³ |
| Milligram per cubic meter | 8570000000 | mg/m³ |
| Kilogram per cubic centimeter | 0,00857 | kg/cm³ |
| Gram per cubic centimeter | 8,57 | g/cm³ |
| Milligram per cubic centimeter | 8570 | mg/cm³ |
| Kilogram per litre | 8,57 | kg/L |
| Gram per litre | 8570 | g/L |
| Milligram per litre | 8570000 | mg/L |
| Kilogram per millilitre | 0,00857 | kg/mL |
| Gram per millilitre | 8,57 | g/mL |
| Milligram per millilitre | 8570 | mg/mL |
Conversion Chart British and U.S.:
| Pound per cubic yard | 14449,02 | lb/yd³ |
| Pound per cubic foot | 535,0251 | lb/ft³ |
| Pound per cubic inch | 0,3096341 | lb/in³ |
| Pound per U.S. gallon | 71,51665 | lb/gal |
| Pound per British gallon | 85,8714 | |
| Pound per U.S. bushel | 665,8033 | |
| Ounce per cubic yard | 231132,9 | oz/yd³ |
| Ounce per cubic foot | 8559,716 | oz/ft³ |
| Ounce per cubic inch | 4,95346 | oz/in³ |
| Ounce per U.S. gallon | 1144,095 | oz/gal |
| Ounce per British gallon | 1374,628 | |
| Ounce per U.S. bushel | 10652,51 |
British Gravitational and English Engineering Units:
| Slug per cubic yard | 448,9823 | slug/yd³ |
| Slug per cubic foot | 16,6258 | slug/ft³ |
| Slug per cubic inch | 0,00962411 | slug/in³ |