:root {
–primary-color: #2c3e50;
–secondary-color: #3498db;
–accent-color: #e74c3c;
–light-bg: #f8f9fa;
–border-color: #e9ecef;
}
body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
}
.calculator-card {
background: #fff;
border: 1px solid var(–border-color);
border-radius: 12px;
box-shadow: 0 4px 15px rgba(0,0,0,0.05);
padding: 30px;
margin-bottom: 40px;
}
.calculator-header {
text-align: center;
margin-bottom: 25px;
}
.calculator-header h2 {
margin: 0;
color: var(–primary-color);
font-size: 24px;
}
.input-group {
margin-bottom: 20px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: var(–primary-color);
}
.input-group input {
width: 100%;
padding: 12px;
border: 2px solid var(–border-color);
border-radius: 6px;
font-size: 16px;
transition: border-color 0.3s;
box-sizing: border-box;
}
.input-group input:focus {
border-color: var(–secondary-color);
outline: none;
}
.calc-btn {
width: 100%;
background-color: var(–secondary-color);
color: white;
border: none;
padding: 14px;
font-size: 18px;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
transition: background-color 0.2s;
}
.calc-btn:hover {
background-color: #2980b9;
}
.results-container {
display: none;
margin-top: 30px;
padding-top: 20px;
border-top: 2px dashed var(–border-color);
}
.result-box {
background-color: var(–light-bg);
padding: 20px;
border-radius: 8px;
margin-bottom: 15px;
text-align: center;
}
.result-label {
font-size: 14px;
color: #666;
text-transform: uppercase;
letter-spacing: 1px;
}
.result-value {
font-size: 32px;
font-weight: 800;
color: var(–primary-color);
margin: 10px 0;
}
.result-value.accent {
color: var(–accent-color);
}
.result-sub {
font-size: 14px;
color: #7f8c8d;
}
.article-content h2 {
color: var(–primary-color);
margin-top: 40px;
}
.article-content h3 {
color: var(–secondary-color);
}
.formula-box {
background-color: #f1f8ff;
border-left: 4px solid var(–secondary-color);
padding: 15px;
font-family: 'Courier New', monospace;
margin: 20px 0;
}
.example-box {
background-color: #fff5f5;
border-left: 4px solid var(–accent-color);
padding: 15px;
margin: 20px 0;
}
@media (max-width: 600px) {
.calculator-card {
padding: 20px;
}
}
function calculateMortality() {
var deathsInput = document.getElementById('totalDeaths');
var popInput = document.getElementById('totalPopulation');
var resultsArea = document.getElementById('resultsArea');
var deaths = parseFloat(deathsInput.value);
var population = parseFloat(popInput.value);
if (isNaN(deaths) || isNaN(population)) {
alert('Please enter valid numbers for both deaths and population.');
return;
}
if (population <= 0) {
alert('Total population must be greater than zero.');
return;
}
if (deaths < 0) {
alert('Number of deaths cannot be negative.');
return;
}
// Calculations
var percent = (deaths / population) * 100;
var per1000 = (deaths / population) * 1000;
var per100000 = (deaths / population) * 100000;
// Display Results
document.getElementById('resultPercent').innerHTML = percent.toFixed(4) + '%';
document.getElementById('resultPer1000').innerHTML = per1000.toFixed(2);
document.getElementById('resultPer100k').innerHTML = per100000.toFixed(1);
resultsArea.style.display = 'block';
}
Understanding the Formula for Calculating Mortality Rate
The mortality rate, often referred to as the death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. It is a critical metric in epidemiology, public health, and actuarial science.
The General Formula
The most common calculation used is the Crude Death Rate (CDR). The formula represents the ratio of deaths to the population size, usually multiplied by 1,000 to make the number more readable.
Mortality Rate = (D / P) × k
Where:
D = Total number of deaths during a specific period
P = Average total population during that same period
k = Multiplier (typically 1,000 or 100,000)
Why Use a Multiplier (k)?
Raw percentages for mortality are often very small numbers (e.g., 0.0084%). By multiplying by 1,000, we convert this to a "rate per 1,000," which is easier to communicate. For rare diseases, epidemiologists often use a multiplier of 100,000.
- Per 1,000 (Crude Rate): Best for general population death rates.
- Per 100,000: Best for specific causes of death (e.g., cancer, accidents).
- Percentage: Used less frequently in professional demographics but helpful for general understanding.
Calculation Example
Scenario: A city has a population of 500,000 people. In one year, there were 4,200 recorded deaths.
Step 1: Divide deaths by population.
4,200 ÷ 500,000 = 0.0084
Step 2: Multiply by 1,000 to get the Crude Death Rate.
0.0084 × 1,000 = 8.4
Result: The mortality rate is 8.4 deaths per 1,000 people.
Types of Mortality Rates
While the calculator above determines the general rate, there are specific variations used in different contexts:
- Crude Death Rate (CDR): Counts all deaths regardless of cause.
- Case Fatality Rate (CFR): The proportion of people diagnosed with a specific disease who end up dying from it. (Input "Deaths from Disease" and "Total Cases" into the calculator).
- Infant Mortality Rate (IMR): The number of deaths of infants under one year old per 1,000 live births.
Factors Influencing Mortality Rate
When analyzing these figures, consider that the rate is heavily influenced by the age structure of the population. A retirement community will naturally have a higher crude mortality rate than a college town, even if the healthcare quality is identical. To account for this, statisticians often use "Age-Adjusted Mortality Rates."