I researched about it, and find there are 3 main methods to do calculations:
• Straight-Line Method:
```Depreciation Expense = (Cost - Salvage Value) / Useful Life```
• Declining Balance Method:
```Depreciation Expense = Book Value at Beginning of Year * Depreciation Rate```
• Sum-of-the-Years'-Digits (SYD) Method:
```Depreciation Expense = (Remaining Useful Life / Sum of the Years' Digits) * Depreciable Cost```
Every method has its needed data