# Reading Sell-Through and Markdown Risk in a Seasonal Buy
A buyer orders 5,000 units of a floral spring dress in November, months before a single customer sees it. By late June, whatever hasn't sold gets cleared out at 60% off to make room for fall. The gap between those two moments is where fashion margins live or die.
Let's trace that one dress from buy to clearance, and watch how weekly sales data tells you, early, exactly how much money you're about to lose.
Fashion runs on seasonal buys: bulk orders placed far ahead of the selling window because factories, fabric, and shipping need lead time. For spring apparel, the buy is often locked 6 to 9 months out.
That timing creates the core problem. You commit cash to inventory before you know if customers want it. Get the quantity wrong on the high side, and you're stuck marking it down.
Our example dress:
At full price, that's $300,000 in potential revenue against $90,000 in product cost. The question is how much of that revenue you actually capture before the clock runs out.
Sell-through rate is the percentage of received units sold over a period. The formula:
Sell-through % = units sold / units received
If you received 5,000 dresses and sold 400 in week one, your week-one sell-through is 8%.
Retailers watch sell-through weekly because it forecasts the endgame early. A healthy seasonal item often targets roughly 60 to 70% sell-through at full or near-full price, with the remainder cleared through planned markdowns. These targets vary by category and retailer, so treat them as directional, not universal.
Here is the key insight: a season is a fixed number of weeks. If sell-through is too slow in weeks 1 through 4, no amount of hoping fixes it. The remaining weeks simply cannot absorb the leftover units at full price.
Watch two dresses over the first four weeks:
| Week | Dress A units sold | Dress B units sold |
|------|-----|-----|
| 1 | 450 | 250 |
| 2 | 500 | 220 |
| 3 | 480 | 200 |
| 4 | 470 | 190 |
Dress A sold 1,900 units in four weeks: a 38% cumulative sell-through. At that pace it clears well before season end. Dress B sold 860 units: 17% cumulative, and the weekly numbers are declining. Dress B is in trouble.
You don't need week 16 to know. By week 4, the trajectory is visible.
To translate the curve into action, buyers use weeks of supply (WOS), an estimate of how long current inventory will last at the recent sales pace:
WOS = units on hand / average weekly units sold
For Dress B after week 4:
The problem is stark. Only about 12 weeks of season remain, but you have roughly 21 weeks of inventory at the current pace. You will end the season with a large pile of unsold dresses unless something changes demand.
That "something" is almost always price.
A markdown is a permanent reduction in retail price to accelerate sales. Markdown risk is the danger that you'll have to cut price deeply to clear inventory, sacrificing margin.
The math of urgency: the later you wait, the fewer weeks remain to sell through, so the deeper the cut has to be. A small markdown in week 6 can move more total units than a desperate 60% cut in week 14, simply because week 6 has more selling weeks ahead of it.
For a plain-English primer on how markdowns and margin interact, the U.S. Small Business Administration's guidance on pricing strategy is a solid, free starting point.
Suppose you act in week 5 and cut Dress B from $60 to $45 (a 25% markdown). Historically, a price cut of that size might lift weekly unit sales meaningfully; assume it roughly doubles the pace to 400 units per week. (This lift is an assumption for illustration; real elasticity varies by brand and product.)
Now the countdown fits inside the season. You still take a margin hit, but you clear the goods and avoid a deeper end-of-season cut.
Compare the two paths on the 4,140 remaining units:
Path 1: act early, 25% off at $45
Revenue on remaining units (if all clear): 4,140 x $45 = $186,300
Path 2: wait, then clear at 60% off ($24) in the final weeks
If demand at that price only clears part of the pile, say 3,000 units, and 1,140 go to a liquidator at $10:
(3,000 x $24) + (1,140 x $10) = $72,000 + $11,400 = $83,400
The early, shallower markdown captures far more revenue. Waiting doesn't preserve margin; it destroys it, because unsold units eventually clear at the worst possible price or get liquidated near cost.
🎬 [VIDEO: "Retail Math: Sell Through, Markdowns and Gross MarginGross MarginGross margin is the share of revenue left after subtracting the direct cost of producing goods or services, expressed as a percentage of revenue.Voir la définition complète →" — https://www.youtube.com/results?search_query=retail+math+sell+through+markdown — a walkthrough of the core retail calculations buyers use every week]
Vérification des acquis
1. Why does a seasonal buy create financial risk that ordinary continuous replenishment does not?
2. A buyer sees week-one sell-through come in well below target. Why is this early signal so valuable?
3. What does the sell-through rate actually measure?
4. Select ALL correct answers about why sell-through targets should be treated as directional rather than absolute.
Sélectionnez toutes les réponses correctes.
5. Select ALL correct answers describing the relationship between sell-through and markdown risk in a seasonal buy.
Sélectionnez toutes les réponses correctes.
The discipline is a loop, run every week:
1. Measure cumulative and weekly sell-through.
2. Convert to weeks of supply and compare against weeks remaining in the season.
3. Act when WOS exceeds the weeks left, taking a shallow markdown early rather than a deep one late.
For Dress A, WOS stays comfortably inside the season, so you hold price and protect full margin. For Dress B, the week-4 data already flags trouble, and a week-5 markdown salvages most of the revenue.
Multiply this across an entire assortment and the stakes get large. Markdowns are one of the biggest drags on apparel gross margingross marginGross margin is the share of revenue left after subtracting the direct cost of producing goods or services, expressed as a percentage of revenue.Voir la définition complète →. Gross margin
Excess seasonal inventory also ties up working capitalworking capitalWorking capital is the difference between a company's current assets and current liabilities, measuring short-term liquidity and the funds available to run daily operations.Voir la définition complète → (cash locked in goods you can't sell), which limits what you can buy for the next season. A buyer who clears cleanly frees cash to invest in winners.
This is why open-to-buy planning, sell-through targets, and markdown cadence are as much finance functions as merchandising ones. The buyer's calendar and the CFO's cash flow are the same story told two ways.
Two cautions. First, sell-through curves are not linear. Newness sells fast in weeks 1 and 2, then slows, so don't over-extrapolate from a single hot week. Second, external shocks (weather, a viral trend, a competitor's promotion) can distort demand. Use the numbers as a disciplined signal, not a guarantee, and revisit the assumptions as fresh data arrives.