Two ovals of the same weight can look completely different. The reason is ratio: the stone's length divided by its width.
What the number does
A higher ratio stretches the stone and slims the finger; a lower ratio looks fuller and softer. A 1.45 oval reads long and elegant, a 1.30 reads rounder and brighter in the centre.
Our favourite ranges
Oval 1.35–1.50 · Pear 1.45–1.75 · Emerald 1.30–1.50 · Marquise 1.85–2.10 · Radiant 1.20–1.35 · Cushion 1.00–1.20.
There is no wrong answer. Ask to see two ratios side by side on video, and trust the one you keep looking at.