What size Princess would match a 0.5 ct Round?

[tjs]

I was at first shopping for a 0.5 ct round diamond to set in a solitaire setting. But I have recently found out my gf is interested in a Princess, which tends to look smaller in size given the same weight.

What weight Princess would you recommend to match the 0.5 round? I've seen some general numbers in past posts (1 ct rnd to 1.25 ct princess, and 1 ct round to 1.5 ct princess). Initially I was shopping around for a 0.6 ct which was around $1200 (AGS0, >G color, >SI1 clarity). Going up to 0.7 ct nearly doubles the price given similar specs

Just wanted your opinions. Thanks! (Side Note: My gf isn't interested as much in size. But I set a personal "goal" to at least give around a 0.5 ct round look)

 

[Garry H (Cut Nut)]

It depends on the princess cut of course, but in general a 0.60-0.61ct would be about the same surface area as a 0.5ct 5.1mm round.

The formula for round surface area is 1/2 diameter x 1/2 diameter times 3.142 - so = 20.43mm squared for 5.1mm round
Surface area of a square is LxW so you need around 4.5mm to be the same surface area.

But princess cuts never have as much light return as equivalently well cut rounds, especially near the edges. So I suggest 4.6 - 4.7mm princess

 

[jaz464]

The chart in this thread may be helpful:

https://www.pricescope.com/community/threads/diamond-size-chart-by-carat-shape.35883/