How do I calculate machine hours

Machine hours or machine hour rate? Can't "calculate" machine hours without knowing time running. Most service required machines have an hour meter on them.

You will need to know several things in order to calculate depreciation using this method:
1. Cost of the equipment
2. Salvage Value (Residual Value) of the equipment
3. Total hours useful life of the equipment.
and 4. Hours used.

First your subtract the Salvage Value from the cost of the equipment to get your depreciable base.
Next divide your depreciable base by total hours of useful life to get your depreciable rate per machine hour.
Finally take your hours used during the period or activity times the depreciable rate per machine hour to get your depreciation amount for the period or activity.