Sell Through Rate Formula: The Complete
Inventory & Retail Guide
Master the sell through rate formula: calculate sell-through by product, compare to plan, and use it for reorder and markdown decisions.
The Sell Through Rate Formula
Available = opening inventory (+ units received in period if applicable)
Quantity sold in the period for the product or group. Use same period as available.
Opening inventory, or opening + received in period. What you could sell in that window.
Percentage of inventory sold. Track by product and period; compare to plan.
Quick Example
200 units available at start of month, 70 sold in the month.
Sell through = (70 ÷ 200) × 100 = 35%
35% of inventory sold. Use targets (e.g. 50% by week 4) to trigger reorder or markdown.
See What’s Selling by Product
StoreRadar shows sales and performance by product and category so you can pair with inventory and improve sell-through decisions.
Sell Through Rate Formula Variations
Basic rate, with receipts, by revenue, and vs plan
Available = opening inventory, or opening + received. Same period for sold and available.
Strict: only inventory you had at start. Sold can't exceed opening.
Available = what you could sell (opening + incoming).
Value of inventory = units × cost or retail; be consistent.
Index > 100 = beating plan; < 100 = under plan.
Worked Examples
Step-by-step sell through rate calculations
Basic Product Sell Through
Product X: opening inventory 400 units. You sold 160 units in the last 4 weeks. No new stock received.
- 1 Opening inventory = 400
- 2 Units sold = 160
- 3 Sell through = (160 ÷ 400) × 100 = 40%
- 4 Remaining = 400 − 160 = 240 units
Sell through rate is 40% in 4 weeks.
At this rate you'd sell full stock in ~10 weeks. Use to compare to plan or other products; consider reorder or promotion if too slow.
Sell Through With New Receipts
Opening 200 units. You received 100 more mid-month. Sold 120 units in the month.
- 1 Available = 200 + 100 = 300
- 2 Units sold = 120
- 3 Sell through = (120 ÷ 300) × 100 = 40%
- 4 Closing = 300 − 120 = 180 units
40% sell through. 180 units left.
Including receipts gives a fair view of what you had to sell. Use for reorder and markdown decisions.
Comparing Products
Two products in same category. Product A: 80 sold, 200 available = 40%. Product B: 45 sold, 150 available = 30%.
- 1 Product A: (80 ÷ 200) × 100 = 40%
- 2 Product B: (45 ÷ 150) × 100 = 30%
- 3 A is selling through faster
- 4 Category blend: 125 sold ÷ 350 available ≈ 35.7%
Product A has higher sell through (40% vs 30%).
Focus reorder and space on A; consider markdown or promotion for B if below plan.
Sell Through Benchmarks
Typical contexts (targets vary by category and period)
| Type | Typical | Notes |
|---|---|---|
| Fashion (full price) | Varies by season | Often 60–80% by end of season |
| Fashion (promo period) | Higher | Markdowns boost sell through |
| Consumer electronics | Slower | Longer lifecycle, plan by quarter |
| Fast-moving consumables | High | Aim to sell most within period |
| Limited / seasonal | Target 80%+ | Minimize leftover stock |
How to Improve Sell Through
Strategies for inventory and merchandising
Plan by Product and Period
Set a target sell through (e.g. 70% in 8 weeks). Track actual vs plan and act when behind.
Markdown Cadence
Define markdown triggers (e.g. 30% sell through at week 4 = first markdown) to clear slow movers.
Reorder Thresholds
Use sell through and lead time to reorder winners before stockout; avoid overordering slow movers.
Assortment Mix
Shift space and buy toward products with consistently high sell through.
Promotions and Bundles
Use targeted promos to lift sell through on specific SKUs or categories.
Liquidate Early
For seasonal or one-off, liquidate early if sell through is below plan to free cash and space.
Common Sell Through Mistakes
Errors that distort the rate
Mixing Time Periods
Using monthly sold with quarterly opening inventory, or weekly sold with monthly available.
Use one period for both: e.g. 'units sold in last 4 weeks' and 'units available at start of those 4 weeks' (or opening + received in that window).
Wrong Denominator
Using closing inventory instead of opening or available, so sold can exceed 'available' or rate is distorted.
Available = what you had to sell in the period (opening, or opening + received). Not closing.
Ignoring New Receipts
Only using opening inventory when you received stock during the period, understating available and overstating sell through.
Include units received in the period in 'available' so the rate reflects true sell-through of all stock you could sell.
Averaging Across Unequal Products
Averaging sell through % across products with very different inventory levels can hide problem SKUs.
Track sell through per product or category. Use weighted average (by units or value) if you need one number.
How to Track Sell Through for WooCommerce
Ways to measure units sold and inventory for sell through
Option 1: Spreadsheets
Export inventory and sales by product from WooCommerce or your ERP. Calculate sell through per SKU and period manually.
- Full control
- No extra cost
- Manual
- Slow
- Hard to keep current
Option 2: Inventory / ERP
Use inventory management or ERP modules that track opening, receipts, and sales. Some calculate sell through or turnover.
- Single source of truth
- Often has COGS
- May not be real-time
- Can be complex
Option 3: StoreRadar
StoreRadar shows what’s selling by product and category. Combine with your inventory data to compute sell through, or use order and revenue trends to spot fast vs slow movers.
- Sales and product performance
- Real-time
- Segments
- Inventory from WooCommerce or link to ERP
Related Formulas
Sell through ties to inventory and margin
| Formula | Calculation | Relationship |
|---|---|---|
| Inventory Turnover | COGS ÷ Average Inventory | Broader measure of how fast inventory turns |
| Sell Through Rate | (Units Sold ÷ Available) × 100 | Same metric; often per product |
| Gross Margin | (Revenue − COGS) ÷ Revenue × 100 | Sell through affects revenue and margin |
| Stock-to-Sales Ratio | Inventory ÷ Sales (same period) | Inverse idea; months of supply |
| Sell Through Index | Actual Sell Through ÷ Plan × 100 | Performance vs plan |
Frequently Asked Questions
Common questions about sell through rate
Sell Through Rate = (Units Sold ÷ Units Available) × 100. 'Units Available' is usually opening inventory + units received in the period (or just inventory at start if you don't receive new stock). For example, 80 sold out of 200 available = 40% sell through. It shows what percentage of inventory you sold in the period.
Sell through rate is (Sold ÷ Available) in a period—a percentage of stock sold. Inventory turnover is Cost of Goods Sold ÷ Average Inventory—how many times you 'turn' inventory in a period. Both measure how fast you sell stock; sell through is often used per product or category; turnover is broader.
For a single product: Units Sold (in period) ÷ Units Available at start of period (or opening + received). Multiply by 100 for percentage. Use the same period (e.g. 4 weeks, 1 month) and same product/SKU. Track by product to see which items sell through fast vs slow.
It depends on category and period. Fashion/seasonal often aims for 60–80% sell through in a season; slow movers might be 20–40%. High sell through can mean understocking (lost sales); low can mean overstock (markdowns). Compare to your own history and plan (e.g. 70% by end of season).
Units are standard: (Units Sold ÷ Units Available) × 100. Revenue-based sell through (Revenue from product ÷ Value of inventory) is possible but mixes price and volume. Use units for consistency and to compare across price tiers.
Low sell through at mid-season often triggers markdowns to clear stock. Sell through rate helps you decide when to promote or discount: if rate is below plan, consider markdowns or campaigns. High sell through may justify reordering or raising prices.
See What’s Selling by Product
StoreRadar shows sales and performance by product and category—so you can improve sell-through and inventory decisions.
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