Inventory Cost Flow — FIFO / LIFO / Weighted Avg (Periodic & Perpetual) • Interactive SVG

Move the sliders to see how **FIFO**, **LIFO**, and **Weighted Average** change **Ending Inventory** and **COGS**. Toggle **Periodic** vs **Perpetual (Moving Avg / LIFO Perpetual)** and adjust when sales happen.

System & Timing Valuation system

ELI5 Periodic = compute once at month-end. Perpetual = update cost **every time you buy** (moving average) and LIFO sells newest **as you go**. To actually see differences, set Perpetual + Sales evenly.

Layers (Beginning + 3 Purchases) Beginning Inventory

Qty

Unit cost (₱)

Purchase 1 — Qty 120 • Unit cost ₱12.00

Purchase 2 — Qty 150 • Unit cost ₱14.00

Purchase 3 — Qty 130 • Unit cost ₱16.00

Units Sold (period total)

Perpetual + “Sales evenly” will split sales into 3 equal chunks (after P1, P2, P3). That’s what makes LIFO & Moving Avg differ from periodic.

FIFO — Ending Inv

FIFO — COGS

LIFO — Ending Inv

LIFO — COGS

WA — Ending Inv

WA — COGS

Method	System	Avg (if WA)	Ending Inv (₱)	COGS (₱)

Exam tips

Rising prices: FIFO → higher Ending Inv, lower COGS. LIFO → lower Ending Inv, higher COGS. WA sits in the middle.
Periodic vs Perpetual: FIFO matches either way; LIFO and Average can differ. Use “Perpetual + Sales evenly” to see it.
COGS + Ending Inv = Goods Available for Sale (guardrail check).

Inventory Cost Flow — Interactive (Periodic & Perpetual)