A yellow gold three-stone ring with three round diamonds on green velvet

Education 5 min read Updated Oct 29, 2026

How Much Is a 3 Carat Lab Grown Diamond?

By Yareli, Founder and Designer

Real Prices From Our Diamond Search

Search 3 Carat Lab Grown Diamonds Shop Engagement Rings

A 3 carat diamond was once out of reach for most couples. Lab-grown, it costs a fraction of a natural stone, and the top grades add surprisingly little. Here is what one costs in our diamond search, how big it looks on the hand, and what a finished 3 carat engagement ring costs.

The experts you can trust: Mine & Grown guides are written with jewelry experts and reviewed for accuracy. Questions about a specific piece? Our team is happy to help.

Isolde round three-stone engagement ring in yellow gold on green velvet, close-up

What a 3 Carat Lab-Grown Diamond Costs

In our diamond search in October 2026, eight in ten 3 carat round lab-grown diamonds with G color or better, VS2 clarity or better and an Excellent cut cost $1,000 to $3,750, each with an IGI or GIA grading report, and the full range runs from $850 to $17,500. We count stones from 3.00 to 3.09 carats with photos, leave out the cheapest and the most expensive tenth for the first range, and round every range out to round numbers.

For the other eight shapes, the eight-in-ten ranges together run from $1,000 to $9,500; the table below gives each shape's own range. Each loose diamond is sourced for your order and arrives in about 2 to 3 weeks.

3 Carat Lab-Grown Diamond Price Ranges by Shape, October 2026

Shape	Eight in ten cost	Lowest to highest
Round	$1,000–$3,750	$850–$17,500
Oval	$1,000–$4,250	$850–$22,500
Pear	$1,000–$7,500	$850–$20,000
Emerald	$1,000–$5,500	$850–$12,500
Radiant	$1,250–$6,000	$900–$37,500
Cushion	$1,000–$5,500	$900–$27,500
Marquise	$1,250–$9,500	$850–$22,500
Princess	$1,000–$5,000	$900–$12,500
Asscher	$1,000–$8,500	$1,000–$12,500

Felora oval engagement ring in white gold on green velvet

How Much Do the Grades Matter?

Less than you might expect. In our search, eight in ten 3 carat rounds with top grades, D to F color, VVS2 clarity or better and an Ideal cut, cost $1,000 to $4,000, against $1,000 to $3,750 for G color or better, VS2 clarity or better and an Excellent cut, and the middle price is only about 16% higher. At this size color and clarity are easier to see, so the top grades are often worth that small step up.

Cut still matters most for sparkle, so keep it Excellent or Ideal. Our guide The 4 C’s of Buying Diamonds explains each grade.

Isolde round three-stone engagement ring worn on the hand

Just Under 3 Carats Costs Less

Prices step up at round-number weights. In our search, eight in ten rounds from 2.90 to 2.99 carats cost $850 to $3,250, against $1,000 to $3,750 from 3.00 to 3.09 carats, and the middle price is about 18% lower, while they look almost the same size on the hand.

Search the full range in our 3 carat and 2 carat diamond searches.

Aurora oval solitaire engagement ring worn on the hand

How Big Is a 3 Carat Diamond?

In our search, a typical 3 carat round measures about 9.3 mm across. Elongated shapes spread the same weight over a longer outline: a typical 3 carat oval measures about 11.7 by 8.2 mm, a pear about 12.8 by 8.0 mm and an emerald cut about 9.8 by 6.8 mm.

Our guide Understanding Diamond Size Before You Buy shows how carat weight translates into size. For the next size down, see How Much Is a 2 Carat Lab Grown Diamond?.

Odessa emerald bezel engagement ring worn on the hand

What a 3 Carat Engagement Ring Costs

Our engagement rings with a 3 carat lab-grown center diamond cost $1,500 to $4,750, and with a 3 carat natural center $40,000 to $85,000, across every design, metal and diamond grade. The setting is made to order in our Chicago studio in about 4 to 6 weeks.

See How Much Does an Engagement Ring Cost in 2026? for every size, metal and diamond origin.

Verona emerald solitaire engagement ring worn on the hand

Lab-Grown vs Natural at 3 Carats

A 3 carat lab-grown diamond is a real diamond with the same hardness and sparkle as a natural one, and the price gap grows with size: a ring with a 3 carat natural center costs about 12 to 42 times as much as the same ring, in the same metal and grade, with a lab-grown one. Both come with an IGI or GIA report that states the diamond's origin.

Read Natural vs Lab-Grown Diamonds for how they compare beyond price.

Sierra oval engagement ring worn on the hand

How to Choose a 3 Carat Diamond

Keep the cut Excellent or Ideal. It decides the sparkle.
Lean toward top color and clarity. At 3 carats they show more, and for lab-grown they cost only a little more.
Look just under 3 carats if you want the same look for less.
Choose a secure setting. Six prongs or a bezel hold a larger stone firmly for everyday wear.
Check the photos and 360° view of each stone, and open its IGI or GIA report.
Ask us. Yareli, our founder and designer, can compare diamonds with you by video or phone.