1. Average annual depreciation method: the amount of depreciation accrued on fixed assets is spread evenly over the estimated useful life of the fixed assets.
Formula: annual depreciation rate = ((1 - expected net salvage rate) / expected useful life) * 100%.
Monthly depreciation rate = annual depreciation rate / 12.
Monthly depreciation = original cost of fixed assets * monthly depreciation rate.
2, workload method: according to the actual workload to calculate the amount of depreciation per period.
Formula: unit workload depreciation = (fixed assets original price * (1 - expected net salvage rate)) / expected total workload.
A fixed asset monthly depreciation = the fixed asset workload in the month * unit workload depreciation.
3, double-declining balance method: generally should be in the two years before the expiration of the useful life of the fixed assets, the net book value of fixed assets less the estimated net residual value of the net amortization.
Formula: annual depreciation rate = (2 / expected useful life) * 100%.
Monthly depreciation rate = annual depreciation rate / 12.
Monthly depreciation = net book value of fixed assets at the beginning of each month * monthly depreciation rate.
4, sum-of-the-years method: the original cost of fixed assets minus the estimated net salvage value of the balance, multiplied by a declining fraction to calculate the annual depreciation.
Formula: annual depreciation rate = (remaining useful life / expected useful life of the sum of the years) * 100%.
Monthly depreciation rate = annual depreciation rate/12.
Monthly depreciation amount = (original cost of fixed assets - estimated net salvage value) * monthly depreciation rate.