HeyGema

Gem sizer

Any stone at its real size, on screen and on the hand.

  • Faces up 6% bigger than a round of the same weight
  • Covers 38% of the finger’s width

Sizes are for a typical cut. A deeper or shallower stone of the same weight faces up a little smaller or bigger.

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How big is a diamond? Size guides

How big is a 1 carat diamond in mm?

A 1 carat round diamond is about 6.5 mm across. A 1 carat oval is about 8.0 x 5.5 mm, a princess cut about 5.5 x 5.5 mm and an emerald cut about 7.0 x 5.0 mm.

How do I see a diamond at its real size?

Pick a shape and carat in the gem sizer. It shows the stone at its real size on your screen once you confirm your device or a bank card, on a finger in your ring size, and in your room with AR on iPhone, iPad and Android.

Can I send the size to my jeweler?

Yes. The gem sizer makes a link with the stones, ring size and metal in it. Anyone who opens it sees the same stone at its real size.

Is a 1 carat sapphire the same size as a 1 carat diamond?

No. A sapphire is denser than a diamond, so a 1 carat sapphire faces up about 4% narrower. An emerald is lighter, so it faces up about 9% wider.