Whatever you can spend without resenting it. That is the honest answer and everything below is the reasoning, because most of the advice you will find on this question was written by people with a reason to want the number to be higher.

Where the three-months-salary rule came from

An advertising agency. De Beers ran a campaign in the 1930s suggesting one month's salary, and by the 1980s the same campaign had raised it to two, then three. It was never a tradition, a custom or a rule of etiquette. It was a sales target, published as folk wisdom, and it worked so well that people still repeat it as though it came from somewhere.

There is no correct percentage of your income to spend on a ring. There is only what you can spend comfortably and what that amount buys.

So what does the average person actually spend?

National averages hover somewhere between two and six thousand dollars depending on whose survey you read, and the figure is skewed upward by a small number of very large purchases. The median — the middle of the actual distribution — sits lower than the average every time. If you spend less than the headline number you are in the majority, not behind it.

More useful than any average: a one carat centre stone is the most common size bought worldwide. If your budget gets you to a carat in solid gold, you are buying the ring most people buy.

What actually drives the price

Four things, in descending order of impact.

The stone is most of it. Carat weight moves the price faster than anything else, and it does not move linearly — the jump from 1ct to 2ct is far more than double, because large rough is disproportionately rare. Whether the diamond is lab-grown or natural is the next biggest lever, and it is a large one: a Lab-Grown Diamond costs a fraction of a mined stone at the same grade, which is how a 1ct D–F, VS+ centre in solid 14K gold lands under two thousand dollars here rather than several times that.

Then the metal. Solid 14K gold versus platinum is a real difference in material cost. Gold weight matters too — a wide band or a heavy cathedral uses measurably more metal than a 1.5mm shank.

Then the setting. A plain solitaire is the least labour. A pavé or French pavé shank, a halo, a hidden halo or a bezel all add bench hours, and bench hours are the honest part of the price.

Then the retailer. This is the one nobody itemises. A mall storefront, its staff, its inventory sitting in cases and its marketing budget are all inside the ticket price. Made-to-order work from one bench has none of that, which is why the same specification costs differently in different places for reasons that have nothing to do with the ring.

Where to spend and where to save

Spend on cut. It is the only one of the four Cs that is entirely about workmanship rather than luck, and it determines whether a stone looks alive or flat. A well-cut smaller diamond beats a badly cut larger one every time, in any light, from any distance.

Spend on clarity if you are buying a step cut. An emerald cut is a window into the stone and shows everything inside it. On a round brilliant the faceting hides a great deal, so you can go lower without anyone noticing.

Save on carat weight before you save on anything else, and save it by choosing shape rather than spending less. An oval, pear or marquise spreads the same carat weight further across the finger than a round does — a 1ct marquise runs about 10mm long against a round's 6.5mm. A princess cut is the best value per carat of any shape, because the cut wastes very little of the rough.

Save on colour in yellow and rose gold. Warm metal disguises warmth in a stone. In white gold or platinum the same grade shows more, so that is where paying up for colour earns its keep.

Does a bigger ring mean more?

No, and it is worth saying plainly because the whole industry is built on implying otherwise. Nobody has ever looked back on a marriage and measured it against a millimetre. What people remember is that the ring suited them, that it was chosen with attention, and that it still looks right twenty years later.

The version of this that actually matters: buy something well made in solid metal that can be serviced for the rest of her life, rather than something larger that cannot.

What if your budget is smaller than you want it to be?

Then buy the best-made ring your budget reaches and understand that it is not a permanent decision. A centre stone can be upgraded later in the same setting, and a setting can be rebuilt around a stone you already own. People do this at anniversaries all the time and it is a normal part of the work.

What you should not do is buy something plated, filled or hollow to reach a size you cannot otherwise afford. Those pieces cannot be resized or repaired, they wear through within a couple of years, and there is nothing underneath to polish back. Solid metal in a smaller size will outlast a larger piece that is mostly not gold.

What does a ring actually cost here?

Everything on the site is solid 14K gold or platinum, set with D–F colour, VS+ clarity Lab-Grown Diamonds, IGI certified at one carat and above, made to order in 7 to 10 business days. There is no storefront in the price and no setting fee on top.

The best way to see where your budget lands is to look at the ranges directly: all engagement rings, or narrow by solitaire, bezel, three-stone and halo settings.

How to decide, in order

Set the number you can spend without resenting it. Choose the shape first, because it changes how large the ring looks more than anything else at the same price — the diamond shape guide covers all of it. Then choose the setting, using the setting guide, because that decides how the ring lives on her hand. Then spend the remainder on cut, and on clarity if you have chosen an emerald cut.

If you tell me your number I will tell you honestly what it reaches and what it does not. That conversation costs nothing and it is the fastest way through this.

Who makes these?

I do. One bench, one pair of hands, in a workshop in Woodside, Queens. I came into the trade in 2016 at a family wedding band factory in Long Island City and trained at Studio Jewelers in Manhattan. Every ring starts as a CAD model I build myself, so the specification is a set of numbers I can adjust to a budget rather than a fixed price on a menu.