Inventory Aging Calculator

This calculator models how fast fashion inventory loses value on the floor and what markdown gets it moving again. Current Perceived Value applies a flat 2%-per-week depreciation to the original retail price (floored at 10% of retail, so nothing depreciates to zero) — a simplification that treats every week on the rack as equally damaging, which is rougher than real seasonal markdown cadences but gives a quick directional read. Suggested Markdown is driven by the gap between your current sell-through rate and your target: for every 10 percentage points you're behind target, the model recommends roughly 15% off (a 1.5x multiplier on the gap), capped at 80% so it never suggests giving product away. That markdown is then applied to the original retail price to produce the Markdown Price.

Projected Weeks to Sell divides your remaining unsold percentage by your average weekly sell-through rate (sell-through rate divided by weeks aged so far) — if the item is brand new (zero weeks old), it falls back to an assumed 5%-per-week pace rather than dividing by zero. Total Holding Cost then multiplies that projection by your per-unit weekly carrying cost. The key limitation: this is a linear extrapolation of past performance, not a forecast — it assumes your sell-through rate stays constant going forward, so it won't catch an item that's about to fall off a cliff (end of season) or one about to accelerate (a viral moment). Use it to flag aging SKUs for review, not as a substitute for a real markdown calendar.