# Average-Decreasing - BC Bookkeeping Tutorials|dwmbeancounter.com

Title
Go to content

## Average-Decreasing

Costing Methods
Average Calculations Using the Perpetual and Periodic Inventory System
Decreasing Prices
We're now going to see the effect of decreasing prices using the Perpetual and Periodic Inventory Methods with Average Costing.

Average Costing

Moving Average with the Perpetual Inventory Method

Our Schedule of Purchases and Beginning Inventory

• Beginning Inventory is made up of 100 units with a cost per unit of \$8.00 for a total cost assigned of \$800.00.

• Purchases of Super Widget made during the year are as follows:

Date                          Quantity        Unit Cost      Extended Cost    Invoice Number    Supplier
January 15, xxxx          200              \$7.50               1,500           A-976123             Acme Products
March 5, xxxx              300              \$7.25               2,175           7898000               Alternate Products
September 10, xxxx     200              \$7.00               1,400           A-999999              Acme Products
December 20, xxxx      150              \$6.75               1,012.50       B-789012             Acme Products

Total Purchases           850                                      6,087.50

Our Stock Record Card (Subsidiary Ledger Card) for Super Widgets assuming an Average Cost Flow appears below:
Weighted Average with the Periodic System

Our Schedule of Purchases and Beginning Inventory

• Beginning Inventory is made up of 100 units with a cost per unit of \$8.00 for a total cost assigned of \$800.00.

• Purchases of Super Widget made during the year are as follows:

Date                          Quantity    Unit Cost        Extended Cost     Invoice Number    Supplier
January 15, xxxx          200          \$7.50              1,500                A-976123            Acme Products
March 5, xxxx              300          \$7.25              2,175                7898000             Alternate Products
September 10, xxxx     200          \$7.00              1,400                A-999999            Acme Products
December 20, xxxx      150          \$6.75              1,012.50           B-789012            Acme Products

Total Purchases           850                                 6,087.50

Using the data from our Schedule, the calculation of the cost used to assign cost to our Ending Inventory and our Cost of Goods Sold is straight forward.

Purchased Dollars   Purchased Units
Beginning Inventory                              \$800.00                  100
Purchases                                          \$6,087.50                  850
Total Cost and Units To Account For      \$6,887.50                  950

Calculation of weighted Average Cost:
Weighted Average Cost Per Unit = Total Costs To Account For / Total Units To Account For
Weighted Average Cost Per Unit = \$6,887.50 / 950
Weighted Average Cost Per Unit = \$7.25

Cost Assigned To Ending Inventory:
Cost Assigned To Ending Inventory = Units On Hand x Weighted Average Cost Per Unit
Cost Assigned To Ending Inventory = 100 x \$7.25
Cost Assigned To Ending Inventory = \$725.00

What about the cost assigned to Cost Of Goods Sold ?

Cost Of Goods Sold Calculation:
Total Dollars To Account For                         \$6,887.50
Less: Costs Assigned To Ending Inventory          725.00
Costs Assigned To Cost Of Goods Sold           \$6,162.50

What's Next ?

Specific Identification Costing Method
Back to content