Replenish at style, colour and size level. Check sellable stock, confirmed incoming pieces, customer holds and days out of stock before applying a sales rate. A style total can hide missing sizes.
The total can look comfortable
Your shop has 25 blue shirts in one style. That sounds enough until a customer asks for medium. You have none. Ten small shirts cannot fulfil that request.
A variant is the specific combination a customer buys: for example, style 410, blue, medium. Shopify's inventory reports calculate stock coverage by variant. Its documentation also warns that no-sales items do not provide enough information for a days-remaining prediction. You can make the following review in a spreadsheet or your existing stock report.
Compare demand and availability together
This fictional example covers the last 14 days in one shop. There were no returns, receipts or customer reservations during the period.
| Size | Pieces sold | Sellable pieces now | Days out of stock | First action |
|---|---|---|---|---|
| S | 2 | 10 | 0 | Check before adding |
| M | 8 | 0 | 6 | Check unmet requests |
| L | 12 | 3 | 0 | Review replenishment |
| XL | 4 | 12 | 0 | Hold further buying for review |
Medium sold eight pieces during eight available days. Dividing by all 14 days produces 0.57 pieces per day and understates the observed rate while stocked. Dividing by eight available days gives one piece per day, but still does not prove demand will continue at that rate. Record missed customer requests and check whether a promotion drove those sales.
Calculate one replenishment proposal
For large, assume a 14-day period to cover supplier lead time and the next buying review. At 12 ÷ 14 pieces per day, expected demand is 12 pieces. The owner chooses an illustrative three-piece buffer. Target stock is therefore 15.
With three sellable pieces now and four confirmed incoming before the stock is needed, the proposal is 15 − 3 − 4 = 8 pieces. Check the incoming order's date before deducting it. Pieces arriving after the selling opportunity cannot fill this week's need.
The buffer is a business choice, not an industry standard. Increase or reduce it using delivery reliability, missed sales, cash available and the remaining season. Do not order an equal-size pack solely because the total order quantity fits the budget.
First seasonal buy or in-season refill?
For a new style, there is no history for that exact item. Use comparable fits and price points, supplier minimums and a small initial commitment where practical. Record why you chose the size split so the next decision has a starting point.
For an established style, use recent variant sales with availability notes. Separate damaged pieces, display-only items and customer holds from sellable stock. Record returns by reason: a sizing problem may call for a different fit, not more pieces of the same size.
Make the buying conversation specific
Instead of “shirts reorder karo,” ask: “Blue 410 mein M aur L ka stock, pending purchase aur pichhle 14 din ki sales dikhao.” Review that answer against the physical rack before approving the order.
Keep a weekly record of proposed quantity, approved quantity and the reason for any change. After the next delivery, compare the result with stockouts and remaining pieces. That builds your own size curve without treating a supplier's pack ratio as customer demand.
Questions you might ask
How do I decide which clothing sizes to reorder?
Review each style-colour-size combination using sellable stock, incoming orders, recent sales and days unavailable. Start with variants whose expected demand exceeds usable supply.
Can I use last month’s size sales as demand?
Use them as evidence, with stockout and promotion notes. A size that was unavailable could have sold more; a seasonal launch may not repeat.