Calculator Form
The calculator uses a 3-column layout on large screens, 2 columns on smaller screens, and 1 column on mobile.
Example Data Table
This sample shows how the calculator works before you enter your own values.
| Label | Age | Income | Age × Income |
|---|---|---|---|
| Group A | 24 | $28,000 | 672,000 |
| Group B | 31 | $42,000 | 1,302,000 |
| Group C | 45 | $56,000 | 2,520,000 |
| Group D | 52 | $39,000 | 2,028,000 |
| Total | 152 | $165,000 | 6,522,000 |
Example weighted average age: 6,522,000 ÷ 165,000 = 39.53 years.
Formula Used
Income Weighted Average Age
Weighted Average Age = Σ(Age × Income) ÷ Σ(Income)
Where:
- Age is the age for each row.
- Income is the matching weight for that row.
- Σ means sum across all valid rows.
Income Share = Income ÷ Total Income × 100
Weighted Median Age is the age where cumulative income reaches 50% of total income.
Weighted Standard Deviation measures the income-weighted spread of ages around the weighted average age.
How to Use This Calculator
- Enter a label for each person, segment, or group.
- Type the age and matching income for every row.
- Choose decimal places and a Plotly chart mode.
- Click Calculate Result to show the result above the form.
- Review summary cards, row details, and the graph.
- Use the CSV or PDF options to save the analysis.
FAQs
1) What does income weighted average age mean?
It is the average age after giving more influence to rows with higher income. Larger incomes contribute more strongly to the final age than smaller incomes.
2) How is this different from a simple average age?
A simple average treats every age equally. This calculator treats income as the weight, so higher-income entries affect the result more than lower-income entries.
3) Can I enter decimal ages or decimal income values?
Yes. The calculator accepts decimals for both fields. That helps when ages are estimated precisely or when income values include cents or fractional amounts.
4) What happens if a row is blank?
Completely blank rows are ignored. Rows with invalid or negative values are skipped, and a warning message appears above the calculator.
5) Why must total income be greater than zero?
The weighted average divides by total income. If total income is zero, the division becomes undefined, so the calculator cannot produce a valid weighted result.
6) What is the weighted median age?
It is the age where cumulative income reaches half of the total income after sorting by age. It shows the midpoint of income distribution across ages.
7) What does the Plotly graph show?
It visualizes either income, age × income contribution, or income share by entry. You can switch the chart mode from the output options panel.
8) Can I download the results for reporting?
Yes. Use the CSV button for spreadsheet analysis or the PDF button for a cleaner report that includes summary metrics and the detailed row table.