Example – FIFO Comparison with Multiple Sales: Periodic vs. Perpetual Inventory

๐Ÿ”ฐ Beginning Inventory (May 31):

  • 100 units @ $10 = $1,000


๐Ÿ“ฆ Purchases:

Date Quantity Unit Cost Total Cost
June 5 200 $11 $2,200
June 20 150 $12 $1,800

๐Ÿ’ต Sales:

Date Quantity Sold
June 10 150 units
June 25 200 units

๐Ÿ“ฆ Physical Inventory on June 30:

  • 100 units


โž• Total Available Before Sales:

Date Units Cost per Unit Total Value
May 31 100 $10 $1,000
June 5 200 $11 $2,200
June 20 150 $12 $1,800
Total 450 $5,000

๐Ÿ“˜ A. FIFO Under Periodic Inventory

FIFO assumes oldest costs sold first, but applies this only at period-end.

Total sold during June = 150 + 200 = 350 units
Ending Inventory = 100 units (from most recent purchases)

๐Ÿ”ข Step 1: Ending Inventory (from newest costs)

To assign cost to 100 remaining units:

  • 100 units from June 20 @ $12 = $1,200

โœ… Ending Inventory = $1,200


๐Ÿ”ข Step 2: COGS

COGS = Total Goods Available โ€“ Ending Inventory
= $5,000 โ€“ $1,200 = $3,800


๐Ÿ“— B. FIFO Under Perpetual Inventory

Here, inventory and COGS are updated after each sale, using FIFO at the time of sale.


๐Ÿ“ Before June 10 Sale

Inventory:

  • 100 @ $10 = $1,000

  • 200 @ $11 = $2,200
    Total: 300 units, $3,200


๐Ÿ“ June 10: Sold 150 units

Sold using oldest costs:

  • 100 @ $10 = $1,000

  • 50 @ $11 = $550
    COGS = $1,550

Remaining inventory:

  • 150 @ $11 = $1,650


๐Ÿ“ June 20 Purchase

  • 150 units @ $12 = $1,800

Inventory now:

  • 150 @ $11 = $1,650

  • 150 @ $12 = $1,800
    Total: 300 units, $3,450


๐Ÿ“ June 25: Sold 200 units

FIFO pulls:

  • 150 @ $11 = $1,650

  • 50 @ $12 = $600
    COGS = $2,250

Remaining inventory:

  • 100 @ $12 = $1,200

โœ… Ending Inventory = $1,200
โœ… Total COGS = $1,550 (June 10) + $2,250 (June 25) = $3,800


โœ… Final Comparison

Periodic FIFO Perpetual FIFO
Ending Inventory $1,200 $1,200
COGS $3,800 $3,800

They Match!

Yes โ€” in this specific scenario, even though sales were spread out, FIFO gave identical results.