Is a 3 carat lab-grown diamond the same size as a natural 3 carat?

Yes, at the same shape and proportions. Carat is weight. Origin does not change the millimeters.

US guides

3 carat loose diamonds and the US budget tradeoff

Natural 3 carat stones with strong grades are priced for rarity. Lab-grown 3 carat stones make the size available to more USD budgets.

The US decision

Tint and inclusions show more. A color grade you accepted at 1 carat can look warm at 3 carats in white gold.

What to verify

Table and depth decide whether the stone faces up like 3 carats or hides weight in the pavilion.

What to do next

Compare a short list around 3 carats instead of buying the first large USD price you can afford. Carat Mate ships the certified loose diamond and its lab report to United States addresses. Prices on the site are in USD. Wrong-item returns may be considered within 3 days of delivery, subject to review.

Questions

Is a 3 carat lab-grown diamond the same size as a natural 3 carat?: Yes, at the same shape and proportions. Carat is weight. Origin does not change the millimeters.