Your Total Fertility Rate (TFR) is:
—
Understanding TFR: A TFR of approximately 2.1 is considered the "replacement level" fertility, meaning that a population is stable and will neither grow nor shrink over the long term, assuming no migration. A TFR below 2.1 suggests a declining population, while a TFR above 2.1 suggests a growing population.
.tfr-calculator-wrapper {
font-family: sans-serif;
max-width: 600px;
margin: 20px auto;
border: 1px solid #ddd;
padding: 20px;
border-radius: 8px;
box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.tfr-calculator-wrapper h2, .tfr-calculator-wrapper h3 {
text-align: center;
margin-bottom: 20px;
color: #333;
}
.calculator-form .form-group {
margin-bottom: 15px;
}
.calculator-form label {
display: block;
margin-bottom: 5px;
font-weight: bold;
color: #555;
}
.calculator-form input[type="number"] {
width: calc(100% – 22px); /* Adjust for padding and border */
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
}
.calculator-form input[type="number"]::placeholder {
color: #aaa;
}
.calculator-form button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
}
.calculator-form button:hover {
background-color: #0056b3;
}
.calculator-result {
margin-top: 30px;
padding: 20px;
background-color: #f9f9f9;
border: 1px solid #eee;
border-radius: 4px;
text-align: center;
}
.calculator-result #result {
font-size: 2rem;
font-weight: bold;
color: #28a745;
margin-bottom: 15px;
}
.calculator-result p {
font-size: 0.95rem;
color: #666;
line-height: 1.5;
}
.calculator-form span {
font-size: 0.85rem;
color: #777;
display: block;
margin-top: 5px;
}
function calculateTFR() {
var rate15to19 = parseFloat(document.getElementById("age15to19").value);
var rate20to24 = parseFloat(document.getElementById("age20to24").value);
var rate25to29 = parseFloat(document.getElementById("age25to29").value);
var rate30to34 = parseFloat(document.getElementById("age30to34").value);
var rate35to39 = parseFloat(document.getElementById("age35to39").value);
var rate40to44 = parseFloat(document.getElementById("age40to44").value);
var rate45to49 = parseFloat(document.getElementById("age45to49").value);
var rates = [rate15to19, rate20to24, rate25to29, rate30to34, rate35to39, rate40to44, rate45to49];
var sumOfRates = 0;
var allValid = true;
for (var i = 0; i < rates.length; i++) {
if (isNaN(rates[i]) || rates[i] < 0) {
allValid = false;
break;
}
sumOfRates += rates[i];
}
if (allValid) {
// The TFR is typically calculated by summing the age-specific fertility rates (ASFRs)
// and then multiplying by the age interval (which is 5 years for these standard groups).
// However, the input values are already 'births per 1,000 women'.
// The standard TFR calculation sums ASFRs (births per woman) for each age group,
// assuming a 5-year interval.
// If inputs are 'births per 1000 women', we need to convert them to 'births per woman'
// by dividing by 1000, then multiply by 5 years, then sum.
// So, (ASFR_group1 / 1000 * 5) + (ASFR_group2 / 1000 * 5) + …
var tfr = (
(rate15to19 / 1000) * 5 +
(rate20to24 / 1000) * 5 +
(rate25to29 / 1000) * 5 +
(rate30to34 / 1000) * 5 +
(rate35to39 / 1000) * 5 +
(rate40to44 / 1000) * 5 +
(rate45to49 / 1000) * 5
);
document.getElementById("result").innerHTML = tfr.toFixed(2);
} else {
document.getElementById("result").innerHTML = "Please enter valid numbers.";
}
}