Vehicle Depreciation

HostMetrics calculates vehicle depreciation for profitability analysis.

Supported Methods

The simplest method — equal depreciation each year.

Annual Depreciation = (Purchase Price - Salvage Value) / Useful Life (years)
Monthly Depreciation = Annual / 12

Example:

Annual = ($35,000 - $10,000) / 5 = $5,000/year
Monthly = $5,000 / 12 = $416.67/month

Accelerated method — higher depreciation in early years.

Annual Depreciation = Book Value x (2 / Useful Life)

Year 1:

35,000 x 0.40 =

14,000 Year 2: (

35,000 -

14,000) x 0.40 =

8,400 **Year 3:** (

21,000 -

8,400) x 0.40 =

5,040 …and so on until salvage value is reached.

Depreciation based on actual miles driven (from trip odometer readings).

Per-Mile Rate = (Purchase Price - Salvage Value) / Expected Lifetime Miles
Monthly Depreciation = Miles This Month x Per-Mile Rate

Example:

Each vehicle can have depreciation configured in the Vehicle Detail page:

Field	Description
Purchase price	Original vehicle cost
Salvage value	Expected value at end of useful life
Useful life (years)	For straight-line and declining balance
Depreciation method	`straight_line`, `declining_balance`, or `mileage`
Purchase date	When the vehicle was acquired
Expected lifetime miles	For mileage-based method only

Monthly depreciation is included in the profitability calculation:

Vehicle Profit = Trip Earnings - Expenses - Depreciation
Profit Margin = (Profit / Earnings) x 100

This gives a more accurate picture of true profitability by accounting for the vehicle’s declining value.

src/lib/depreciation.ts — Contains all three depreciation calculation methods.