| Nominative | gigahertz |
| Genitive | gigahertzu |
| Dative | gigahertzu |
| Accusative | gigahertz |
| Vocative | gigahertze |
| Locative | gigahertzu |
| Instrumental | gigahertzem |
| Nominative | gigahertzy |
| Genitive | gigahertzů |
| Dative | gigahertzům |
| Accusative | gigahertzy |
| Vocative | gigahertzy |
| Locative | gigahertzech; gigahertzích |
| Instrumental | gigahertzy |