Carry the smallest number of SKUs that lets a customer find what she came for and buy it in her size. SKU count is not a measure of how serious your boutique is. It is a measure of how much complexity you have taken on, and every SKU costs money, space and attention whether it sells or not. The useful question is not how many you should have, but which ones are earning their place.
I am Carina Hatton, boutique owner since 2013 and ecommerce coach since 2019. Figures on this page are labelled hypotheticals used to demonstrate the arithmetic.
Quick answer
What a SKU actually is
A SKU, or stock keeping unit, is a single uniquely identifiable version of a product. If two things need to be counted separately in your inventory, they are separate SKUs.
The distinction people miss is the one between styles, SKUs and units:
| Term | What it means | Example |
|---|---|---|
| Style | One product design, regardless of variants | One linen wrap dress |
| SKU | One specific variant of that style | That dress in sage, size medium |
| Unit | One physical item you own | The three sage mediums on the rack |
So a single dress in two colours and five sizes is one style, ten SKUs, and however many units you bought across them. That multiplication is the whole reason SKU counts surprise people.
The multiplication that catches owners out
Hypothetical example. Say you plan a modest apparel launch:
- 12 styles
- Each in 5 sizes
- Four of them also in a second colour
SKU count: 12 styles × 5 sizes = 60, plus 4 styles × 5 sizes for the second colour = 20 more. That is 80 SKUs from what felt like twelve products. If you then bought three units of each SKU, that is 240 units of inventory and 80 separate things to track, photograph decisions around, restock and count.
Now add accessories. Twenty jewelry styles with no variants add twenty SKUs, which is comparatively light. Five handbag styles in two colours add ten. The point is that apparel multiplies and accessories mostly do not, which is why accessory-heavy boutiques can carry more products with far less operational weight.
How many SKUs by boutique format
| Format | What limits SKU count | How to think about it |
|---|---|---|
| Online boutique | Photography, listing time, and cash spread across variants | Fewer styles with full size coverage beats many styles with gaps |
| Storefront | Physical floor and rack space, and how full the room must look | Space sets a floor on total units, which pushes SKU count up |
| Pop-up or market | What you can transport, set up and restock in a day | Deliberately narrow, with depth in a few proven items |
| Apparel-only | Size runs multiplying every style | SKU count climbs fast, so style count should stay disciplined |
| Mixed category | Attention across unrelated categories | Non-sized categories add products cheaply in SKU terms |
A pop-up is the clearest illustration of the principle. Nobody brings their whole catalogue to a market, because the constraint is obvious and physical. The same constraint exists online, it is just invisible, which is why online assortments sprawl.
Sample assortment structures
All hypothetical, shown to illustrate how style count converts to SKU count.
Narrow online apparel launch
- 10 styles, one colour each, 5 sizes: 50 SKUs
- Plus 15 accessory styles with no variants: 15 SKUs
- Total: 65 SKUs, 25 products a customer sees
Mixed-category small storefront
- 18 apparel styles, 5 sizes, 5 of them in two colours: 115 SKUs
- 25 jewelry styles: 25 SKUs
- 6 handbag styles in 2 colours: 12 SKUs
- 12 gift and impulse items: 12 SKUs
- Total: 164 SKUs, 61 products a customer sees
Pop-up or market stall
- 6 apparel styles, 4 sizes: 24 SKUs
- 10 accessory and gift items: 10 SKUs
- Total: 34 SKUs, with real depth in the three proven sellers
Notice the gap in each case between SKU count and the number of products a customer perceives. Customers shop styles. Your system, your cash and your time are spent on SKUs.
Sizes and colours are the real decision
Size variants are usually not optional. If you sell apparel, a customer who cannot find her size does not buy a different size, she leaves. Cutting size coverage to reduce SKU count is almost always the wrong economy, and it is the reason a lot of small apparel boutiques have disappointing conversion.
Colour variants are optional, and they are where SKU count should be controlled. Every additional colour of the same style is a bet that demand splits in a way you have measured. Before you take a style in two colours, ask whether you would rather have a second style entirely. Usually you would, because a second style reaches a customer the first one did not.
The exception is a proven repeat seller, where a second colour is a low-risk way to extend something that already works.
What SKU count does to inventory management
Each SKU carries an ongoing cost that has nothing to do with whether it sells:
- It has to be received, counted and entered correctly
- It appears in every stock count you ever do
- It needs a location, physical or logical, so staff can find it
- It generates a restock decision every cycle, even if the answer is no
- It occupies attention during every review, dividing the time you have for the products that matter
Two hundred SKUs is not twice the work of a hundred, it is closer to twice the work plus the cost of no longer being able to hold the whole assortment in your head. That threshold is real and it arrives sooner than people expect. Setting the systems up properly is covered in boutique inventory management.
When adding SKUs helps
- A size is selling out repeatedly and you are turning customers away
- A proven style has clear demand for a second colour, based on what customers ask for
- You have a genuine gap in the assortment, such as no gift-price item or nothing at a higher price point
- An adjacent category would let existing customers buy more per visit
- Sell-through across the current assortment is healthy and you are consistently running out
The common thread is that the addition solves a problem you can name. If you cannot name the problem, the SKU is not solving one.
When adding SKUs creates dead inventory
- Adding variety to a category that is not selling, in the hope that variety is the issue
- Taking extra colours because the vendor discount improves at a higher order value
- Adding a new category before the existing ones are turning
- Buying sizes beyond the range you can actually serve well
- Filling space for the sake of looking stocked rather than to meet demand
- Adding items nobody has asked for and nothing in your data points to
Dead SKUs are worse than they look, because they consume the same cash and attention as live ones while returning nothing, and they usually end in markdowns that also drag down your realised margin.
Pruning is as important as adding
A healthy assortment loses SKUs as well as gaining them. On a fixed review schedule, look for:
- SKUs that have not sold a single unit through a full selling cycle
- Sizes that consistently strand at the ends of a run, which should change what you buy next
- Colours where one clearly dominates and the other is subsidising nothing
- Styles held at low stock for months, occupying a listing without being buyable in most sizes
- Anything you keep only because it was expensive to buy, which is a sunk cost, not a reason
Rank them rather than judging by feel. The Sell-Through Calculator gives you the ordering, and the Markdown Sale Calculator tells you what clearing them costs.
Expanding the assortment over time
The disciplined way to grow SKU count is to make it earn its way in rather than deciding a target and buying toward it:
- Grow the assortment when sell-through says the current one is too small, not on a calendar
- Fund additions from sales, not from the launch budget, and keep the addition inside your open-to-buy limit
- Add one dimension at a time, either a new style or a new variant of a proven one, so you can tell what worked
- Retire something when you add something, at least while you are still small
- Re-check whether your systems and your counting routine still cope at the new size
Keeping the ongoing spend tied to actual sales is exactly what open-to-buy for small boutiques is for, and the timing of restocks sits in the Reorder Point Calculator.
Common mistakes
- Treating SKU count as a sign of how established the boutique is
- Cutting sizes instead of cutting colours when trying to simplify
- Letting a vendor's discount tier decide how many variants you carry
- Adding a new category while the current one has not turned
- Never removing anything, so the assortment only ever grows
- Growing past the point where the inventory system and counting routine still work
What to do next
- Count your current SKUs honestly, including every size and colour variant
- List the SKUs that have not sold in a full cycle and decide what happens to each
- Set your style count first, using how many styles to start with, then let the variants follow
- Set depth per style with how many units per style to buy
- Check the total against your budget in how much inventory to start a boutique with