You have equal quantities of bikini tops and bottoms, yet customers cannot find the combinations they want. A medium top may remain in stock while the matching large bottom is sold out.
Planning bikini top and bottom size ratios means making two linked inventory decisions. Start with how the pieces will be sold, then build separate quantity lines for each garment, color and size.
Decide whether the customer buys a set or separates
A fixed set ties one top to one bottom. Separates let customers choose different sizes, but that also means each piece needs its own stock record. State the selling format before sending a quantity breakdown to the factory.
Keep coordinated skirts or cover-ups on their own lines too. Matching fabric does not make two garments the same stock item. The broader first swimwear order planning guide covers the overall assortment; this worksheet focuses on the quantities within it.
Read sales alongside availability
If you have sales history, separate top and bottom sales by style, color and size. Record returns and exchanges as well as units sold. Compare similar selling periods rather than combining a full-price launch with a clearance week.
Also note how long each size was available. A size that sold few units because it stocked out early is different from one that remained available throughout the period. Orders show completed purchases, not every combination a customer wanted but could not buy.
| Record | Question it helps answer |
|---|---|
| Net units sold by SKU | Which pieces actually left inventory after returns? |
| Days available | Did a stockout limit the observed sales? |
| Top and bottom combinations | Which mixed-size pairings appeared in orders? |
| Exchange reasons | Was the problem allocation, fit or size communication? |
| Remaining companion pieces | Could buyers still complete a coordinated purchase? |
Build two size curves
Calculate the share of top sales represented by each top size, then do the same calculation separately for bottoms. Do not copy the first curve into the second merely because the garments share a collection name.
As an arithmetic illustration, 12 medium tops out of 40 top sales represent 30% of those top sales. That percentage is not a recommended buying ratio or a forecast. Check availability and the strength of the underlying evidence before using it in a new order.
For a first launch, label your quantities as assumptions. Customer interviews, fitting feedback and genuine preorders can inform them, but a small survey should not be presented as proven demand. Keep a review date so the first allocation becomes something you learn from.
Check both totals and combinations
Review the proposed quantities with the supplier. Confirm whether minimums apply by garment, style, color or size, and whether tops and bottoms can have different breakdowns. Keep the written agreement with the order sheet.
Then test the combinations you expect to offer. Identical top and bottom totals do not guarantee that the desired sizes line up. Decide whether you will sell unmatched pieces independently, reserve quantities for sets or change the proposed assortment.
Separate fit corrections from inventory corrections
If customers repeatedly exchange one size, investigate the reason before simply ordering more of the next size. The measurement chart, fit or customer-facing size information may need review. Use the swimwear size grading guide for the product-development side of that decision.
Keep the final purchasing file simple: one SKU per row, confirmed quantities, allocation assumptions and a named review date. After launch, compare the plan with actual availability and net sales before approving a reorder.
Send Joy Bikini your proposed top and bottom breakdown to confirm which quantities and combinations can be quoted for your collection.