Where the “three months’ salary” rule came from

It came out of a marketing campaign. In September 1938 Harry Oppenheimer of De Beers met Gerold Lauck, president of the advertising agency N.W. Ayer & Son, because diamond prices had fallen and the United States was De Beers’ one large market for engagement stones. Ayer’s answer was to tie diamonds to romance and love.

In 1947 an Ayer copywriter, Frances Gerety, wrote the line “A diamond is forever”, still recognized as the greatest advertising tagline of the 20th century. By then the share of American brides with a diamond ring was rising fast, from about 10 per cent in 1940 to some 80 per cent in 1980.

The spending guideline was part of the same marketing. Early De Beers advertisements suggested about one month’s salary for an engagement ring, and by the 1980s the question had become how to make two months’ salary last forever. The table sets out the sequence.

The advertising suggested one month in the 1930s and two months by the 1980s. Three months is the version people quote now, and it has stuck even though it is not the figure the campaign used in its early years.

What matters is the pattern. A figure that moved from one month to two was not measuring what a ring should cost. It moved with the goals of the advertising, which was to sell more diamonds. It tells you what a campaign suggested, not what a person in your position should spend.

No. No law, regulator or standards body backs it, and a salary multiple leaves out most of what decides whether a purchase is comfortable.

• Which salary? Three months of gross pay and three months of take-home pay are very different amounts.
• Where you live. Rent or a mortgage takes a different share of pay in different cities, so the same salary leaves different room.
• Debts and savings. A multiple ignores student loans, a car payment, a down payment fund and an emergency cushion.
• Paying in cash or borrowing. Spending three months of pay on a card is a different decision from spending it from savings.
• The rest of the plan. A wedding band, a wedding and a honeymoon come out of the same money.

A ring is also something you buy to give and wear, not a way to store money. Do not plan on getting the purchase price back if you sell it later.

Start from a cash figure you can pay without borrowing, after your emergency fund and other goals, and treat it as a ceiling, not a target. A wedding band, a wedding and a honeymoon come out of the same money, so count them in before you count the ring. Then decide what you want most from the ring and spend there. The engagement ring budget guide sets out the steps and the methods side by side.

Once you have a ceiling, decide what you want most from the ring and put the money there. Size, quality, shape, metal and stone type all move the price in different directions. The engagement ring budget guide walks through those trade-offs, and the diamond 4Cs guide explains what each grade means.

Stone type changes the price too. A natural diamond, a lab-grown diamond and moissanite are priced differently from one another, and the lab-grown vs natural guide compares them, including what each gives up.

Shape counts as well. Some shapes show more surface for their weight, as covered in why oval diamonds look bigger, so a smaller carat weight in the right shape can look larger than you expect.

Change the ring before you change the budget. Lower the carat weight a little, choose a different quality grade, consider another stone type, or choose a simpler setting. A custom design lets you move each of those separately, so you can keep the part you care about most.

If you are still working out the number, bring your ceiling and a few ideas to an appointment. The custom engagement rings service starts from the shape, setting and stone you want, the design studio lets you explore options, and the showrooms are where you can try rings on.