In children's retail the unit of planning is not the style, it is the style multiplied by the size. Ten styles across eight sizes is eighty decisions, and a buyer who treats it as ten decisions ends up with a rack of the sizes nobody asked for. Everything below is about controlling that multiplication while still having the right size on hand when a parent walks in.
I am Carina Hatton, boutique owner since 2013 and ecommerce coach since 2019. There is no universal children's size curve; the distribution depends on your customers and your age focus. What follows is method plus clearly labelled hypothetical examples.
Quick answer
Planning a first collection or new drop? Use the Boutique Inventory Planner to estimate revenue, profit, and overbuying risk before you order.
Open the Boutique Inventory Planner →Plan by age bracket before you plan by size
Age brackets behave like separate departments with separate customers and different buying rhythms.
| Bracket | Typical sizes | Behaviour |
|---|---|---|
| Newborn and infant | Newborn, 0 to 3m, 3 to 6m, 6 to 9m, 9 to 12m | Very fast size turnover, heavy gift purchasing, year-round demand |
| Baby into toddler | 12 to 18m, 18 to 24m | Transition zone, labelling varies between vendors |
| Toddler | 2T to 5T | Daily wear, durability matters, parent-driven |
| Kids | Roughly 4 to 12 | Widest range, school seasonality, the child has opinions |
Two practical consequences. First, the infant brackets move through sizes so quickly that a garment bought at three months is gone by six, which is why depth in any single infant size should be modest and reorder speed matters more than initial quantity. Second, the kids bracket has the most sizes and therefore the highest cost to cover properly, so do not add it casually to an infant-focused store.
Allocating budget across brackets
A hypothetical $7,500 opening buy for a baby-focused store with a small toddler extension:
| Bracket or category | Share | Hypothetical amount |
|---|---|---|
| Newborn and infant apparel | 35% | $2,625 |
| Toddler apparel | 15% | $1,125 |
| Gifts and keepsakes | 20% | $1,500 |
| Accessories | 10% | $750 |
| Practical goods | 5% | $375 |
| Reorder reserve | 15% | $1,125 |
Thirty-five percent of the budget on size-free products is deliberate. Gifts and accessories carry no variant cost, so they buy you product breadth and a fuller-looking store without consuming the size budget.
Depth by size
Units for a style = number of sizes carried × average depth per size
Size share = units sold in that size ÷ total units sold in that bracket
Sell-through by size = units sold in that size ÷ units received in that size
A hypothetical toddler style at 2T to 5T with a $480 budget at $12 landed cost is 40 units. Spread evenly that is ten per size. Weighted toward the middle of the range it might be six, thirteen, thirteen and eight. The weighted version is almost always the better first guess, because demand across a size range tends to cluster rather than sit flat, and the extremes of any range are the slowest.
After a season, replace the guess with measured data, exactly as in the calculation below.
| Size | Received | Sold | Sell-through | Action next buy |
|---|---|---|---|---|
| 2T | 60 | 34 | 57% | Reduce depth |
| 3T | 80 | 73 | 91% | Increase, demand was cut off |
| 4T | 80 | 76 | 95% | Increase |
| 5T | 55 | 31 | 56% | Reduce depth, keep represented |
Anything above roughly 90% sell-through was supply-limited, so its real demand is higher than the sales figure shows. Anything under about 55% was overbought. Use both numbers together; share alone will mislead you whenever a size sold out early.
Case packs and prepacks
Many children's vendors sell case packs with a fixed size assortment, often something like one of the smallest size, two each of the middle sizes and one of the largest.
- On a first order, take the case pack. You have no data, and the vendor's assortment is a reasonable starting guess
- After a season, compare the case pack against your own curve and ask about open stock
- Count the cost of the sizes the pack forces on you. Two slow units per style across fifteen styles is thirty units heading for markdown
- Check whether the vendor will let you reorder single sizes mid-season, which matters more here than the initial pack composition
Minimum order mechanics are in minimum order quantity, and vendor-level detail in the children's wholesale guide.
Basics, fashion and gifts
| Type | Depth | Reorder | Markdown risk |
|---|---|---|---|
| Basics: bodysuits, leggings, tees | Deep, full size range | Continuous | Low |
| Fashion and prints | Shallow, strongest sizes only | Within the trend or season window | High |
| Seasonal and occasion | Tight, planned to clear | Rarely, timing is everything | Very high after the date |
| Gifts and keepsakes | Deep, no size variants | Continuous | Low |
Occasion wear deserves particular caution. A holiday dress unsold on December 26 is worth a fraction of its cost and cannot wait a year in a size that the customer's child has outgrown. Buy it tight and plan the markdown from the start. The general unit question is in how many units per style should a boutique buy.
Seasonal transitions
| Season | Order window | Inventory note |
|---|---|---|
| Spring | Previous autumn | Flow deliveries rather than taking it all at once |
| Summer and swim | Winter | Clear fully, sizes will not fit the same child next year |
| Back to school | Spring | Biggest size-refresh event, weight basics heavily |
| Holiday | Summer | Peak gift revenue, gifts carry no size risk so buy them deeper |
The structural point: in adult apparel, leftover seasonal stock can sometimes be held for next year. In children's it usually cannot, because the customer for that size has moved on. Treat seasonal children's apparel as perishable and plan clearance into the buy.
A hypothetical first buy
For the $7,500 budget above, working through the infant apparel line of $2,625:
- Choose a modest style count so each style can carry the size range properly
- Weight the buy toward the sizes that gift givers reach for, which skews slightly larger than newborn because parents are often given too many newborn items
- Favour basics and everyday pieces over prints on the first order, so the data you collect is about size rather than taste
- Keep to three or four vendors so you can learn each one's actual sizing
- Reserve the 15% restock money and use it within the first six weeks
The general framework is in how to split your first wholesale order and quantities in how much inventory to start a boutique.
Tracking and reorders
- Create a variant per size so every sale records the size, not just the style
- Report size share and sell-through separately for each age bracket
- Log sell-out dates, since an early sell-out is your strongest reorder signal
- Watch the transition sizes, where vendor labelling disagrees most
- Review before each seasonal buying appointment, not at the end of the year
| Signal | Action |
|---|---|
| Middle sizes gone, extremes remain | Normal. Reorder the middle, shift weight next season |
| Whole style cleared quickly | Reorder full run, treat as core if it is a basic |
| Slow in every size | Style problem. Mark down, do not reorder |
| One bracket outperforming | Shift budget share toward it next season |
| Seasonal item still on hand at season end | Clear it now, it will not survive to next year |
Method is in sell-through rate, control in open to buy, and the cost of holding too long in inventory carrying cost.
Markdown risk and clearing
Children's inventory ages in two directions at once: the season passes and the size becomes irrelevant to your existing customers. Clear earlier than instinct suggests.
- Set a review date at the buy, not after the item stalls
- Stage reductions rather than making one deep cut
- Bundle leftover sizes into gift sets, which reframes slow stock as a gift purchase
- Email customers whose previous purchases suggest the child has now grown into the leftover size
Run the numbers in the Markdown Calculator and check margin impact in the Profit Margin Calculator.
A first order worked line by line
Abstract allocation percentages only become useful when you turn them into an order sheet. Here is the infant apparel portion of the $7,500 budget above, at $2,625, worked through as one hypothetical example.
Units affordable = category budget / average landed cost
Styles = units affordable / units per style
Units per size = units per style x that size's share
At an average landed cost of $11, the $2,625 buys about 238 units. Choosing a depth of 20 units per style gives roughly twelve styles. Applying a mid-weighted spread across five infant sizes, a single style of 20 units might come out as two in the smallest size, five, six, five and two across the rest.
| Style type | Styles | Units each | Total units | Rationale |
|---|---|---|---|---|
| Everyday basics | 5 | 24 | 120 | Reorderable spine, deepest buy |
| Print and seasonal | 4 | 16 | 64 | Reads taste at lower risk |
| Sets and gift-ready outfits | 3 | 18 | 54 | Higher ticket, gift buyers |
That comes to 238 units and roughly the budget. Notice the deliberate imbalance: basics get both more styles and more depth, because they reorder continuously and almost never need marking down, while prints are held shallow because a print that misses cannot be sold at full price once the season turns.
Where children's buys go wrong
| Error | Consequence | Correction |
|---|---|---|
| Even spread across all sizes | Middle sizes gone in weeks, extremes marked down | Weight the curve, then refine with data |
| Too many styles, one or two units each | Nothing is ever in the size a customer asks for | Fewer styles, real depth |
| Adding an age bracket without adding budget | Every bracket becomes too thin to serve | Add brackets only with funding behind them |
| No reorder reserve | Proven sellers cannot be restocked | Hold back roughly 15% of each buy |
| Trusting labels over measurements | Exchanges cluster in one brand | Measure samples and map to your own chart |
| Late seasonal delivery | Goods arrive after the selling window | Confirm delivery and cancel dates in writing |
The reserve deserves the last word. In a category where a best-selling basic in the middle sizes can clear in a month, the ability to reorder quickly is worth more than a wider opening assortment. A buyer who spends every dollar on the first order has traded away the one advantage that reliable data gives, which is the chance to put more money behind the thing that is already working.
Keep the season's total under control with open to buy, read the cost of anything that lingers in inventory carrying cost, and check pricing decisions in the Profit Margin Calculator.
Related: how to start a baby and children's boutique and children's wholesale vendors.