1.5 Carat Diamond Prices

What a 1.5 Carat Diamond Actually Costs

1.5 carat is a popular milestone weight. The diamond market prices every tier of carat weight in steps, not a smooth curve, and milestone weights like this one sit right at a psychological threshold. That means you pay a disproportionate premium for hitting a round number. But it also means the available inventory is deepest here, so you have the most choice.

We're tracking 2,590,865 active listings at 1.5 carat right now. A typical natural diamond in this range costs around ￥1,092,818 JPY while the lab-grown equivalent sits at roughly ￥121,647 JPY, about a 9.0× ratio. That gap is normal because lab-grown has been trending down in price steadily while natural holds value.

ROUND accounts for about 33% of 1.5 carat inventory. Consistent with round being the classic engagement ring choice. Fancy shapes (oval, pear, cushion) trade at slight discounts per carat compared to round, partly because they use more of the original rough crystal so they're cheaper to produce.

At 1.5 carat, the sweet spot for most buyers is D color with SI1 clarity. This combination is eye-clean, face-up indistinguishable from a D/FL on paper, and typically costs 40-60% less. The money you save there is far better spent on cut grade. Excellent or Ideal. Because cut drives sparkle more than any other single grade.

A word on threshold pricing: a 0.95 carat and a 1.00 carat stone of identical quality can differ in price by 15-25%, even though visually they look the same on a finger. If 1.5 carat is a hard target, consider stones just below (0.90-0.99, 1.90-1.99, 2.90-2.99). They face up identically and the savings are real.