The House Guide to Diamonds
Carat is a weight, not a size - and the same stone can look modest on one hand and magnificent on another. Below, see any shape and carat drawn to scale on your own finger, and let the House guide you to the size that is truly yours.
Shown to scale: the stone and the finger share one exact ratio, so what you see is how big it reads on the hand. Screens vary, so this is relative size, not a printed ruler.
Not sure? Most women's fingers are a US 5-7. You can refine it with us later.
The House suggests
One carat is 0.20 grams, split into 100 points. Because weight grows with volume, doubling the carat does not double the width - a 2.00 ct round is only about 25% wider face-up than a 1.00 ct, not twice as big. This is why the studio above measures what you actually see: the width across the finger.
Shape changes everything - how large a stone reads, how it flatters the hand, and how it catches the light. Elongated shapes (oval, pear, marquise, emerald) lengthen the finger and wear larger per carat; brilliant cuts sparkle hardest; step cuts trade sparkle for a calm, mirror-like clarity. Tap Try in the studio on any shape to see it on your finger.
A stone reads relative to the finger it sits on. On slender fingers, a 1.00 ct already makes a confident statement; on a broader hand the same stone can read as understated. The studio does this maths for you - it is why we ask your ring size first.
If you want size, an elongated cut is your friend. An oval, marquise or pear covers more of the finger than a round of the same weight, so you can reach the look you want for less carat - and less cost.
Points and sharp corners (marquise, pear, princess) are more exposed and want a protective setting for daily wear. Rounds, ovals and cushions are the most forgiving everyday stones. Tell us how it will be worn and we will set it accordingly.
Cut quality outranks raw size: a smaller, beautifully cut stone outshines a larger dull one. We guide most clients to the size that reads well on the hand, then put the budget into cut, clarity and colour that hold up close.
The F. BINSABBAR Promise
Every diamond we set into a Creation has cleared a strict house brief - natural origin, untreated, certified by the most rigorous laboratory, and traceably sourced. What that means in practice:
Every stone is earth-formed. We do not source, broker or set lab-grown diamonds under any circumstance.
No HPHT, irradiation, fracture filling, laser drilling or coatings. Every characteristic is the diamond's own.
Every stone arrives with a verifiable report from a leading laboratory - GIA, HRD or AGS. We never accept lenient certs.
Rounds are held to Triple Excellent - Excellent cut, polish and symmetry. Fancy shapes are vetted to comparable proportion standards.
Kimberley Process compliant, sourced through long-standing partners with a documented chain of custody.
Every cert, measurement and plot is shared in full. Nothing is hidden, nothing is hedged.
Stones are hand-picked against the brief above, then examined loose under the loupe for how they truly perform in light - not just how they grade on paper.
The setting is drawn around your stone and your hand, in the studio and in 3D, so proportion, height and finger-fit are right before any metal is cut.
Our goldsmiths hand-build the mount and set each stone by hand - claws, rails and grains tuned so the diamond is secure and lit from every angle.
Finished, quality-checked and delivered with its certificate and a record held for you in the House - so its story stays with the piece.
The next step
When you have a size and shape in mind, our concierge will show you loose stones that match - the full 4 Cs, certificate and measurements - and let you try each against your own finger before anything is set. Book a private viewing or send us your studio selection to begin.
Every measurement on this page is indicative and drawn to typical proportions. Exact face-up size varies with a stone's individual cut - your concierge will confirm the real figures for any stone you consider.