Turn the months-of-salary rule into a real number you can shop with
| Annual Salary | 1 Month | 2 Months | 3 Months | % of Year (2-mo rule) |
|---|---|---|---|---|
| $40,000 | $3,333 | $6,667 | $10,000 | 16.7% |
| $50,000 | $4,167 | $8,333 | $12,500 | 16.7% |
| $60,000 | $5,000 | $10,000 | $15,000 | 16.7% |
| $75,000 | $6,250 | $12,500 | $18,750 | 16.7% |
| $100,000 | $8,333 | $16,667 | $25,000 | 16.7% |
| $150,000 | $12,500 | $25,000 | $37,500 | 16.7% |
Notice the problem: two months of salary at $40,000 is $6,667 — still 45% above the $4,600 national average spend. The rule scales with income while actual spending doesn't, which is the strongest sign it was written by the seller, not the buyer.
| Center Stone (round solitaire) | Natural, Typical Retail | Lab-Grown, Typical Retail |
|---|---|---|
| 0.5 carat | $1,000 – $2,500 | $300 – $700 |
| 1.0 carat | $3,500 – $6,500 | $800 – $1,800 |
| 1.5 carats | $6,000 – $11,000 | $1,500 – $2,800 |
| 2.0 carats | $12,000 – $22,000 | $2,500 – $5,000 |
| 3.0 carats | $30,000 – $55,000 | $4,500 – $9,000 |
Typical retail ranges for mid-grade specs (G-H color, VS1-SI1 clarity, excellent cut) at major online jewelers, 2025-2026. Settings add $300 (simple solitaire) to $2,500+ (halo, pave). Fancy shapes run 10-40% below round. Lab-grown stones are chemically identical to mined diamonds; the discount is supply, not quality.
Two inputs do the real work: your salary and which months-of-salary guideline you want to test. The calculator converts the rule into dollars, brackets it with a ±20% range (the spread most jewelers say shoppers actually land within), and shows what the same budget buys if the stone is lab-grown instead of mined. It also does the two comparisons people skip: your number against the national average, and the monthly saving it takes to get there without financing.
Budget = annual salary × months ÷ 12. Range = budget ± 20%. Percent of salary = months ÷ 12. Lab-grown equivalent = budget × 0.25 for the same visual result, or — flip it — the same budget buys roughly 3-4× the carat weight. Monthly savings = budget ÷ 12. Insurance = 1-2% of value per year, the range standalone jewelry policies typically quote.
Enter gross annual salary and try all three rules. Watch what happens when you switch the stone type to lab-grown: the same visual ring collapses to a quarter of the price, which is the single biggest lever in 2020s ring shopping. Then read your number honestly against the $4,600 average — if your rule output is 3× the average, ask whether the rule or your budget is the outlier.
Take a $65,000 salary with the classic two-months rule. Budget = 65,000 × 2 ÷ 12 = $10,833, with a comfortable range of $8,667 to $13,000. That's 16.7% of the year's gross income, or $903 a month saved across twelve months. As a natural stone it buys roughly a 1.5-carat round solitaire at mid specs; the same visual ring lab-grown runs about $2,700, or you can hold the $10,833 budget and carry a stone pushing 3 carats. Compare the rule's $10,833 to the $4,600 average and the gap is 2.4× — that's the De Beers premium, and it's yours to decline.
Don't forget the tail costs: at 1.5% of value, insuring a $10,833 ring runs about $163 a year, and state sales tax can add several hundred dollars at checkout.
The average US couple spends about $4,600, according to The Knot's 2025 Jewelry & Engagement Study. As a share of income that's roughly 6% of a median household's annual earnings. The old "two months' salary" guideline lands far above what most people actually pay, so treat it as an upper anchor from a 1980s ad campaign, not a rule.
De Beers. The company advertised "one month's salary" for a diamond in the 1930s after the Great Depression, then raised the suggested sacrifice to two months in 1980s campaigns. It was brilliant marketing, never a financial guideline, and it conveniently scales with whatever you earn.
At typical retail prices, $10,000 buys a natural round solitaire around 1.5 carats at mid-grade specs, or a lab-grown diamond at 2.5 carats or more with room left for the setting. The same visual size costs roughly 70-80% less grown in a lab than mined, which is why many 2025-26 budgets overshoot what buyers actually need.
Yes, dramatically. Lab-grown diamonds are chemically identical to mined ones and typically cost 70-80% less for the same carat and specs. A budget sized by the two-months rule usually buys a noticeably bigger or cleaner stone when it's lab-grown, or the same stone for a fraction of the price.
Budget an extra 5-10% on top of the ring for sales tax, resizing (first one is often free, later runs $50-150), and future maintenance like prong tightening. If you insure the ring, standalone jewelry policies typically run 1-2% of the ring's value per year, so a $10,000 ring costs about $100-200 annually to insure.
Saving first is almost always cheaper. Financing at a typical store rate can add 10-20% to the real cost of the ring, and starting a marriage with consumer debt for a depreciating purchase is a trade-off worth questioning. If you do finance, use a 0% intro APR card with a payoff plan inside the intro window, not a store card.