Advanced
Flexible inputs: enter Age (years), DOB (YYYY-MM-DD / DD-MM-YYYY), or patterns like
23y 6m.
| # | Name / ID | Age or DOB | Weight | Include | |
|---|---|---|---|---|---|
|
Tip: Ages like
34, dates like 1994-05-10, or mixed formats. |
|||||
Example Data Table
These are illustrative rows; use the "Load Example" button to insert into the editor above.
| # | Name | Age or DOB | Weight |
|---|---|---|---|
| 1 | Ayesha | 1998-10-20 | 1.0 |
| 2 | Usman | 27 | 1.0 |
| 3 | Sara | 23y 6m | 2.0 |
| 4 | Ali | 2001-02-05 | 1.0 |
| 5 | Fatima | 31 | 0.5 |
Formula Used
Arithmetic mean: \(\bar{x} = \frac{1}{n}\sum_{i=1}^{n} x_i\)
Weighted mean: \(\bar{x}_w = \frac{\sum_{i=1}^{n} w_i x_i}{\sum_{i=1}^{n} w_i}\), where \(w_i \ge 0\).
Age from date of birth: computed as elapsed time from DOB to today, converted to years by dividing days by 365.2425.
Invalid or out-of-range rows are excluded from calculations.
How to Use This Calculator
- Click Add Row or Load Example to populate the table.
- In the Age or DOB column, input a number, a date, or a pattern like
21y 3m. - Optionally enable Use weights and set a weight for each row.
- Adjust Decimals, Min, and Max as needed.
- Press Calculate to compute mean, median, min, and max.
- Toggle Show chart to visualize the age distribution.
- Use Download CSV or Download PDF to export your results.
FAQs
Enter plain ages (e.g.,
34), dates like YYYY-MM-DD or DD-MM-YYYY, or mixed text such as 23y 6m. The tool auto-detects valid formats.We compute the exact time difference between today and the date of birth, then convert the difference to years using 365.2425 days per year.
Use the Min/Max filters to exclude unrealistic ages. Review flagged cells and decide whether to correct or exclude them from analysis.
Each row gets a weight. The mean becomes the sum of age times weight divided by the sum of weights. Rows with missing weights are ignored when weighting is enabled.
Rows may be invalid due to non-parsable ages, dates in the future, negative values, or ages outside your Min/Max bounds.
Yes. Use the CSV button to export raw rows and results, or the PDF button to export a nicely formatted summary with your dataset.
We use your device’s current date/time when converting dates to ages. If precision is critical, consider specifying a reference date consistently.
Age Bands Reference
Typical descriptive bands to contextualize computed means.
| Band | Range (years) | Approx. Midpoint | Notes |
|---|---|---|---|
| Infant | 0–1 | 0.5 | Use months-to-years conversion for precision. |
| Child | 1–12 | 6.5 | Elementary and pre-teen years. |
| Teen | 13–19 | 16 | Often analyzed as early vs late teens. |
| Young adult | 20–35 | 27.5 | Higher education and early career cohorts. |
| Adult | 36–55 | 45.5 | Mid-career population. |
| Older adult | 56–75 | 65.5 | Often grouped for health studies. |
| Senior | 76+ | 82 | Use open-ended bin; report separately if needed. |
Months to Decimal Years (Quick Reference)
Helpful for converting infant records into decimal years for analysis.
| Months | Decimal Years |
|---|---|
| 0 | 0.0000 |
| 1 | 0.0833 |
| 2 | 0.1667 |
| 3 | 0.2500 |
| 4 | 0.3333 |
| 5 | 0.4167 |
| 6 | 0.5000 |
| 7 | 0.5833 |
| 8 | 0.6667 |
| 9 | 0.7500 |
| 10 | 0.8333 |
| 11 | 0.9167 |