How It Works
Move the age slider anywhere from 18 to 80 and choose a formula. The calculator returns a minimum and maximum partner age, the width of that window in years, and an estimate of the singles inside it.
With the comparison toggle on, all three formulas appear side by side. A progression list also shows how the standard range grows from age 20 to 60.
The three formulas
- Standard rule: the familiar half your age plus seven benchmark and its inverse.
- French rule: a stricter version that adds 10 instead of 7.
- ±15% rule: keeps partners within 15% of your own age in either direction.
Every minimum is floored at 18, so no formula ever suggests a partner below adult age.
What Is the Formula?
Standard rule
French rule
±15% rule
- A: your age in whole years.
- ⌊ ⌋: round down to a whole year.
- max(A, …): stops the upper limit dropping below your own age at younger ages.
The singles estimate is (Max minus Min) ÷ 62 × 117 million, where 62 is the 18 to 80 adult span. Choosing men or women applies an extra 0.49 factor.
Dating Age Range Chart by Age
Compare the three formulas at common ages. Each cell shows the minimum and maximum partner age.
| Your age | Standard rule | French rule | ±15% rule |
|---|---|---|---|
| 20 | 18 to 26 | 20 to 20 | 18 to 23 |
| 25 | 19 to 36 | 22 to 30 | 21 to 29 |
| 30 | 22 to 46 | 25 to 40 | 26 to 35 |
| 35 | 24 to 56 | 27 to 50 | 30 to 40 |
| 40 | 27 to 66 | 30 to 60 | 34 to 46 |
| 45 | 29 to 76 | 32 to 70 | 38 to 52 |
| 50 | 32 to 86 | 35 to 80 | 43 to 57 |
| 60 | 37 to 106 | 40 to 100 | 51 to 69 |
At 20 the French rule collapses to your own age, which shows how strict it is for young adults. Past about 50, the doubling formulas stop setting a practical upper limit.
Worked Example
A 34 year old checks their window using the standard rule.
- Minimum: ⌊34 ÷ 2⌋ + 7 = 17 + 7 = 24.
- Maximum: (34 minus 7) × 2 = 27 × 2 = 54.
- Window: 54 minus 24 = 30 years, labelled a Wide Window.
- Singles estimate: 30 ÷ 62 × 117,000,000 ≈ 56.6 million, shown as ~57M.
Switching to the French rule narrows the range to 27 to 48, and the ±15% rule tightens it further to 29 to 39.