Tools · Matchmaker New York
Age Gap Calculator (With the Half-Your-Age-Plus-Seven Rule)
Enter two birth dates to get the exact age gap in years, months and days. The calculator also checks the half-your-age-plus-seven rule for both people: the youngest "acceptable" partner is half your age plus seven. Any gap passes once the younger person is at least 14 years older than the gap.
Your dates stay in your browser. Nothing is saved.
Enter two birth dates to see your age difference.
What is the half-your-age-plus-seven rule?
The half-your-age-plus-seven rule sets a youngest partner age of your age ÷ 2 + 7. Reverse the formula to find the oldest partner age: (your age − 7) × 2. At 30, the range is 22 to 46. Check both people’s ranges.
For a gap of d years, the younger person meets the formula at d + 14. A 10-year gap therefore passes when the younger partner is 24 and the older partner is 34. The same gap can pass the formula later in life.
The formula appears in Max O’Rell’s 1901 book, Her Royal Highness Woman, chapter IV. O’Rell presents it as something he had heard, so the book documents the saying rather than establishing its inventor. Its original wording addressed a man choosing a wife; this tool applies the arithmetic to either person.
The shortcut follows directly: younger ≥ (younger + d) ÷ 2 + 7 ⇔ younger ≥ d + 14.
| Your age | Youngest by the rule | Oldest by the rule |
|---|---|---|
| 18 | 16.0 | 22 |
| 20 | 17.0 | 26 |
| 22 | 18.0 | 30 |
| 25 | 19.5 | 36 |
| 28 | 21.0 | 42 |
| 30 | 22.0 | 46 |
| 35 | 24.5 | 56 |
| 40 | 27.0 | 66 |
| 45 | 29.5 | 76 |
| 50 | 32.0 | 86 |
| 60 | 37.0 | 106 |
| 70 | 42.0 | 126 |
The rule’s lower limit can fall below 18; the calculator does not apply dating rules to anyone under 18.
Is 23 and 30 an okay age gap?
Ages 23 and 30 fall within the half-your-age-plus-seven range. For the 30-year-old, 30 ÷ 2 + 7 = 22, so 23 is above the minimum. For the 23-year-old, (23 − 7) × 2 = 32, so 30 is below the maximum. Then discuss life stage, commitment and your timeline for children.
What is the 7-year rule, and the 7-7-7 rule?
People asking about a “7-year age gap rule” usually mean half-your-age-plus-seven. The seven is an addition to half your age, rather than a fixed seven-year difference. At 30 the youngest age is 22; at 40 it is 27. The permitted gap grows as the people involved get older.
The 7-7-7 rule describes a couples’ habit: a date every seven days, a weekend away every seven weeks and a holiday every seven months. It is a social-media trend about spending time together, with no age calculation involved.
What is the average age gap in US couples?
The average husband was 2.1 years older in our tabulation of Census CPS ASEC 2025 opposite-sex married couples. The mean absolute gap, counting either direction, was 3.8 years. Those figures describe different things: a signed average offsets older wives against older husbands, while an absolute average counts every gap positively.
About half of these marriages had spouses within two years of each other. A gap of at least 10 years occurred in 8.2%. The table shows the directional bands, so the larger husband-older share does not disappear inside a single average.
| Age gap | Share of couples |
|---|---|
| Wife 10+ years older | 1.5% |
| Wife 6–9 years older | 2.5% |
| Wife 4–5 years older | 3.3% |
| Wife 2–3 years older | 7.0% |
| Within 1 year | 35.9% |
| Husband 2–3 years older | 19.9% |
| Husband 4–5 years older | 12.2% |
| Husband 6–9 years older | 11.2% |
| Husband 10–14 years older | 4.3% |
| Husband 15–19 years older | 1.4% |
| Husband 20+ years older | 1.0% |
Source: our tabulation of Census CPS ASEC 2025, 27,675 opposite-sex married, spouse-present couples, weighted by the husband’s March supplement weight. Ages are top-coded at 80/85; 1,585 couples are affected. Figures checked October 30, 2026.
Pew Research Center reports an average husband–wife gap of 2.2 years in 2022, down from 4.9 in 1880. Pew found 51% within two years in 2022. These are married-couple figures, rather than a forecast of the people available to date. For local context, explore single New Yorkers by age.
Do age gaps matter in relationships? What research says
Buunk, Dijkstra, Kenrick and Warntjes’ 2001 study measured acceptable partner ages. In Theresa DiDonato’s reading, men’s youngest acceptable ages roughly followed the formula, while their oldest stayed near their own age. Women’s youngest acceptable ages were higher than the formula allowed. The formula therefore did not reproduce the full pattern of preferences.
Lehmiller and Agnew (2008) found women with younger partners were the most satisfied and committed compared with women with older partners and similar-age couples. Lee and McKinnish (2018), using Australian household survey data, found men were more satisfied with younger wives and women with younger husbands. That advantage disappeared within six to ten years of marriage.
For your own relationship, ask what each person expects now and what might change. A discussion of future responsibilities gives you something concrete to work with.
What age gaps do matchmaking clients ask for?
At Matchmaker New York, we start an age-range conversation with the life someone wants to build. An age preference can stand for several things: wanting children, having time to travel, sharing an active routine or finding someone at a similar career stage. We ask which of those needs the age range is meant to serve.
My view, as Vadim Litvak, is to distinguish a firm boundary from a familiar habit. If you would consider someone just outside your preferred range who shared your plans, tell us that. A strict range removes everyone beyond its endpoints before you can consider their individual fit.
Discuss your relationship non-negotiables and explore our matchmaking services before setting a search range.
Frequently asked questions
What is the golden rule for age gap?
There is no single golden rule for an age gap. Half-your-age-plus-seven is the best-known formula: divide your age by two and add seven for the youngest partner, or subtract seven and double for the oldest. Use the result as a conversation starter, rather than a relationship decision.
Is a 10-year age gap too much?
A 10-year age gap does not answer whether two adults fit together. Under the formula, the younger partner must be at least 24. In practice, discuss children, work, money and how you spend your time. A shared plan matters more than getting a passing result from a dating age calculator.
Is a 20-year age gap relationship okay?
Two adults can choose a relationship with a 20-year gap. The formula is met when the younger person is 34 and the older person is 54. Talk directly about retirement, caregiving, family plans and independence. Each person should have equal room to set boundaries and make decisions.
How do you calculate age difference in months?
Count full calendar years between the birth dates, multiply by 12, then add the remaining full months. Keep leftover days separate. This calculator also shows total days and weeks from the dates themselves; dividing days by 30 would only approximate months, because calendar months have different lengths.
Is the calculator private?
Yes. The calculation runs in your browser. Birth dates and optional names are never sent, saved or included in a share link. The share link contains whole-year ages only. Anyone who receives that link can see those ages; leave the link unshared if you prefer to keep them private.