How do I forecast stock for bestselling ring sizes?

ZKZ Editorial TeamMain answer · Product & gemmology desk

Use your own sales by size, by style and by customer region, not a general chart. We could not find a verified source for the most common ring sizes, so we do not give one. Start small, learn from real orders and keep the rare sizes make-to-order.

What we verified

Fact JCK reported on 21 April 2026 that market analysts described lab-grown diamond inventory rising markedly faster than sales and that slower sell-through ties up capital.

A simple forecasting method

1. Collect sales and returns by size for each style over a set period.
2. Convert counts into a share by size. Treat small samples with caution.
3. Split stock into core sizes, which you hold, and tail sizes, which you make to order.
4. Set a reorder point: expected sales during the lead time plus a safety margin.
5. Review each month and adjust.
6. Track resizing requests, as they show where your range is missing.

Our advice Hold fewer units of each size in more styles, only when each style is tested, and do not stock every size of every style.

Our advice Use a pre-order or made-to-order route for large and small sizes.

It depends Sizes differ by market, product type and customer group, so a forecast from one channel may not hold in another.

Using the first months of data

Our advice In the first months you will have few sales, so avoid strict rules. Order a small, balanced run in the sizes your own customers ask for, record every sale and every enquiry that you could not fill, and update the plan monthly. After a few months you can set reorder points by size. Keep a log of sizes you had to resize, because it shows where guidance on measuring was unclear.

Our advice Do not copy a forecast from one product to another. A thin band and a wide ring may sell in different sizes, and fit differs.

Uncertain We did not verify the most common ring sizes for any country, or the effect of size on returns.

Related reading: How many ring sizes should a first collection stock? · How to Find Your Ring Size at Home (Free Printable Method)

Sources

• JCK, rising demand for lab-grown diamonds

Fact = stated by the cited source. Our advice = editorial recommendation. Uncertain / it depends = limits of what can be said in general.