A style has been on the floor for six weeks and needs a decision — reorder, hold, or start planning a markdown — before deciding, you want the actual sell-through number rather than a gut feeling.
Sell-Through Rate & Inventory Turn Calculator
Retail & Inventory
Sell-through % = (Units sold ÷ Units received) × 100
Weeks of stock remaining = (Received − Sold) ÷ (Sold ÷ Weeks)
Sell-through rate is one of the most important retail health metrics — it tells you whether a style is moving as expected relative to how much stock was brought in.
Reference: Standard retail sell-through rate calculation
Estimate only for business planning purposes. Verify against your actual costs, supplier quotes and local regulations before pricing or committing to a production run.
1 What this calculator does
Calculates the percentage of received stock that has sold (sell-through rate) and projects how many weeks of stock remain at the current sales pace. A core retail metric for deciding whether to reorder, hold, or markdown a style.
2 Formula & professional reasoning
Sell-through % = (Units sold / Units received) x 100
Weekly sale rate = Units sold / Weeks elapsed
Weeks of stock remaining = (Units received - Units sold) / Weekly sale rate
Sell-through rate is one of the most widely used retail health metrics because it directly answers the key inventory question: is this stock moving at the rate expected, or is it stuck? Raw units sold alone doesn't answer this — a style that sold 50 units could be a huge success (if only 60 were bought in) or a slow mover (if 200 were bought in). Combining sell-through percentage with a weekly sale rate and projected weeks of remaining stock gives a forward-looking view, supporting timely reorder, hold or markdown decisions rather than reactive ones made too late in the selling season.
3 Worked examples
⚠️ Illustrative example only — not clinical or professional instruction.
Basic
Strong early sell-through
Given: 60 units received, 48 sold, 3 weeks elapsed
Working:
Sell-through = 48/60x100 = 80% | Weekly rate = 48/3 = 16/week | Remaining = 12/16 = 0.75 weeksAnswer: 80.0% sell-through — Strong, consider reordering
💡 At this pace, remaining stock will sell out in under a week — a clear signal to reorder if the style is still in season.
Standard
Healthy mid-season pace
Given: 120 units received, 78 sold, 6 weeks elapsed
Working:
Sell-through = 78/120x100 = 65% | Weekly rate = 78/6 = 13/week | Remaining = 42/13 = 3.2 weeksAnswer: 65.0% sell-through — Healthy, on track
💡 This is a solid, sustainable sell-through pace — no urgent action needed, but worth monitoring as the season progresses.
Advanced
Slow mover needing intervention
Given: 200 units received, 54 sold, 8 weeks elapsed
Working:
Sell-through = 54/200x100 = 27% | Weekly rate = 54/8 = 6.75/week | Remaining = 146/6.75 = 21.6 weeksAnswer: 27.0% sell-through — Slow, consider markdown or promotion
💡 At this pace, remaining stock would take over 21 weeks to sell through — well beyond a typical selling season, signalling a need for markdown, bundling or promotional action.
4 Sanity check
Sell-through benchmarks (general retail guide)
80%+ in the first few weeks: very strong, consider reorder | 40-80%: healthy, on track | Under 40% partway through the selling season: slow, consider intervention
These benchmarks vary by category, season stage and business model — use as a general guide, not an absolute rule
Timing matters as much as the percentage
A 40% sell-through rate is very different in week 2 of a 12-week season versus week 10 — always interpret sell-through relative to how much of the planned selling season has elapsed
Compare across styles, not just in isolation
Sell-through rate is most useful compared against other similar styles from the same season — a style performing below your typical range for that category is the real signal, not an absolute percentage threshold
Weeks of stock remaining assumes a constant sale rate
This projection assumes the current sales pace continues — seasonal factors (upcoming markdown periods, weather, promotions) can change the actual pace significantly
5 Common errors
| Error | Cause | Consequence | Fix |
|---|---|---|---|
| Comparing sell-through rate without considering season timing | Judging a 50% sell-through rate as 'the same' whether it's early or late in the planned selling season | The same percentage means very different things depending on how much selling time has elapsed | Always interpret sell-through rate relative to the proportion of the planned selling season that has passed, not as a standalone absolute number |
| Using total historical units sold instead of a defined time period | Calculating sell-through using lifetime sales without specifying the time period, especially for ongoing/replenished styles | Weekly sale rate and weeks-remaining projections become meaningless without a clear, consistent time period | Always specify and use a clear, consistent time period (e.g. 'first 6 weeks since receipt') for sell-through and sale rate calculations |
| Ignoring seasonality and one-off sales spikes | Projecting weeks of stock remaining from a sale rate that included a one-off event (holiday sale, viral social post) unlikely to repeat | Overestimates ongoing sell-through pace, leading to under-ordering or missed markdown timing | Consider whether the sale rate used reflects 'normal' ongoing demand or an unusual spike, and adjust projections accordingly |
| Treating low sell-through as always meaning 'discount immediately' | Reflexively marking down any style with sell-through below a target percentage without considering the cause | Some slow sell-through is due to poor placement, insufficient marketing or wrong size run — not necessarily wrong pricing — and a premature markdown erodes margin unnecessarily | Investigate the likely cause of slow sell-through (placement, visibility, sizing, marketing) before defaulting to a markdown as the only lever |
6 Reference & regulatory links
7 Professional workflow
Common tools used alongside this one:
Markdown/Clearance Discount Calculator
For slow-moving stock, calculate a markdown price that still protects some margin
→
Marketplace Fee & Profit Calculator
If moving slow stock to a marketplace clearance channel, check real profit after fees
→
Break-Even Units Calculator
Compare sell-through pace against the units needed to break even on the original production run
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