All comparisons > Grades & Buying
1.00 Carat
The round number
VS
0.90 Carat
The smart miss
1.0 Carat vs 0.9 Carat
The ten percent nobody can see. Round-number pricing is real, and this page is about pocketing it.
Best for the milestone itself: 1.00 ctBest for value: 0.90 ct
| 1.00 Carat | 0.90 Carat | |
|---|---|---|
| Face-up diameter (round) | About 6.4 to 6.5 millimeters | About 6.2 to 6.3 millimeters |
| Visible difference on a hand | The benchmark | A fraction of a millimeter; invisible in practice |
| Price | Carries the round-number premium | Often double-digit percent cheaper for comparable grades |
| Why the gap exists | Demand spikes at milestone weights | Jewelers call these shy weights; demand dips just under the line |
| Same trick elsewhere | Applies at 1.50, 2.00, and every milestone | 0.95, 1.40, 1.90 all enjoy the same discount |
| The catch | None, besides price | Selection is thinner; cutters aim for the round numbers |
Pick 1.00 Carat if
- Hitting the milestone genuinely matters to her or to you
- You found a superbly cut stone that happens to be 1.00
- Budget is not the constraint
Pick 0.90 Carat if
- You would rather spend the gap on cut quality or the setting
- Nobody in your life is weighing the stone
- A slightly thinner selection is an acceptable trade
Cut still outranks weight
A gorgeous 0.90 with top cut beats a mediocre 1.00 in every room it enters, because sparkle is what eyes register. Shop cut first, then let weight land wherever the bargains are hiding, which is usually just under the round numbers.
Say the quiet part kindly
If she has said one carat out loud, this is not the place to be clever. The shy-weight trick is for buyers optimizing on their own; stated wishes outrank arithmetic every time.