Total Fertility Rate Calculator
Period total fertility from actual ASFRschedule, not completed cohort fertility. Caller supplies complete nonoverlapping relevant age bands and matching definitions; no observed individual lifetime prediction.
Description
Total fertility rate integrates age-specific fertility rates over age-band widths.
Total fertility rate integrates age-specific fertility rates over age-band widths.1
It describes a synthetic lifetime under the observed period schedule rather than an individual forecast.
When to use Total Fertility Rate Calculator
Use this tool to obtain conditionalLifetimeBirths from the supplied records using the stated calculation. Establish the population, period, variable definitions, sample coverage and independently applicable instrument or calibration.
How to use Total Fertility Rate Calculator and understand its results
- Establish the population, period, variable definitions, sample coverage and independently applicable instrument or calibration.
- Enter observedAsfrPer1000, ageBandWidthsYears, using the field meanings and rules below, then run the tool.
- Read result.conditionalLifetimeBirths. Use the units and sign conventions below, and review any unknown records separately.
- Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedAsfrPer1000 | Observed asfr per1000 | list of number | Required |
| ageBandWidthsYears | Age band widths years | list of number | Required |
Supply nonempty aligned nonnegative ASFR values per thousand and positive age-band widths in years. Multiply the matched terms for each band, sum and divide by one thousand. The tool does not verify age-band nonoverlap, complete reproductive-age coverage or rate applicability.
lifetimeBirths=Σ(ASFR_i×bandWidth_i)/1000 Use the matching field units and the exact boundary, ordering and reference rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Calculated observation or qualified reference | object |
| result.conditionalLifetimeBirths | Synthetic lifetime sum of the matched age-band terms described in the formula, scaled from ASFR per thousand. | number |
{
"input": {
"observedAsfrPer1000": [
100,
200
],
"ageBandWidthsYears": [
5,
5
]
},
"output": {
"result": {
"conditionalLifetimeBirths": 1.5
}
}
}Limitations and assumptions
Population definitions, survey design, calibration and observation coverage are independently established. A result describes the supplied record or conditional model without demonstrating causation, validating an instrument or supplying representative population evidence.
Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite. Lists and matrices must be dense, without missing cells. Numeric lists allow at most 10000 entries, subject to the narrower lengths and code rules above. Extremely large composite outputs are rejected.
Alternative or Complementary methods
For a related step, use Net Reproduction Rate Calculator: Net reproduction combines age-specific fertility, female-birth fractions and survival to reproductive ages. For a complementary comparison, use Gross Reproduction Rate Calculator: Gross reproduction combines age-specific fertility with female-birth fractions.
References
-
Total Fertility Rate Calculator — tool.io
Similar or alternative tools
- Net Reproduction Rate Calculator
Net reproduction combines age-specific fertility, female-birth fractions and survival to reproductive ages.
- Gross Reproduction Rate Calculator
Gross reproduction combines age-specific fertility with female-birth fractions.