Period Calculator
body {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
line-height: 1.6;
color: #333;
background-color: #f8f9fa;
margin: 0;
padding: 20px;
}
.calculator-container {
max-width: 700px;
margin: 30px auto;
background-color: #ffffff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
border: 1px solid #e0e0e0;
}
h1, h2 {
color: #004a99;
text-align: center;
margin-bottom: 25px;
}
.input-section, .result-section {
margin-bottom: 30px;
padding-bottom: 30px;
border-bottom: 1px solid #eee;
}
.input-group {
margin-bottom: 20px;
display: flex;
flex-wrap: wrap;
align-items: center;
justify-content: space-between;
}
.input-group label {
flex: 1;
min-width: 150px;
margin-right: 15px;
font-weight: 500;
color: #555;
}
.input-group input[type="number"],
.input-group select {
flex: 2;
padding: 10px 15px;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box; /* Include padding and border in the element's total width and height */
font-size: 1rem;
transition: border-color 0.3s ease;
}
.input-group input[type="number"]:focus,
.input-group select:focus {
outline: none;
border-color: #004a99;
box-shadow: 0 0 0 2px rgba(0, 74, 153, 0.2);
}
button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #004a99;
color: white;
border: none;
border-radius: 4px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
margin-top: 10px;
}
button:hover {
background-color: #003b80;
}
.result-display {
background-color: #e7f3ff;
padding: 20px;
border-left: 5px solid #004a99;
text-align: center;
border-radius: 4px;
}
.result-display h3 {
margin-top: 0;
color: #004a99;
font-size: 1.3rem;
}
.result-display p {
font-size: 1.8rem;
font-weight: bold;
color: #28a745; /* Success Green */
margin-bottom: 0;
}
.article-section {
margin-top: 40px;
background-color: #fff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
border: 1px solid #e0e0e0;
}
.article-section h2 {
text-align: left;
color: #004a99;
margin-bottom: 20px;
}
.article-section p, .article-section ul, .article-section li {
color: #555;
margin-bottom: 15px;
}
.article-section ul {
list-style-type: disc;
margin-left: 20px;
}
.article-section li {
margin-bottom: 10px;
}
@media (max-width: 768px) {
.input-group {
flex-direction: column;
align-items: flex-start;
}
.input-group label {
margin-bottom: 10px;
margin-right: 0;
}
.input-group input[type="number"],
.input-group select {
width: 100%;
}
.calculator-container {
padding: 20px;
}
}
Period Calculator
Next Period Estimated Dates:
—
Understanding Your Menstrual Cycle and Period Prediction
The menstrual cycle is a natural and complex series of changes a woman's body goes through each month in preparation for the possibility of pregnancy. It's regulated by hormones, primarily estrogen and progesterone. Understanding your cycle is key to predicting your period, ovulation, and managing your reproductive health.
Key Terms:
- Menstrual Period: The shedding of the uterine lining, resulting in menstrual bleeding.
- Cycle Length: The total number of days from the first day of one period to the first day of the next period. This can vary significantly between individuals and even for the same individual from month to month.
- Period Length: The duration of menstrual bleeding, typically lasting between 3 to 7 days.
- Ovulation: The release of an egg from the ovary, usually occurring around the middle of the cycle.
How the Period Calculator Works
This calculator provides an estimate for your next menstrual period based on your input. It uses a simplified, common method of prediction:
- Starting Point: It takes the start date of your last menstrual period as the reference point.
- Cycle Length: It adds your average cycle length (days from the start of one period to the start of the next) to the start date of your last period. This estimates the start date of your upcoming period.
- Period Duration: It then estimates the duration of your next period by adding your average period length to the calculated start date.
The Math Behind the Calculation
The core calculation involves date arithmetic:
Estimated Next Period Start Date = Last Period Start Date + Cycle Length (in days)
To calculate the estimated end date:
Estimated Next Period End Date = Estimated Next Period Start Date + Period Length (in days) – 1 (We subtract 1 because the start date is included in the count of days).
Example Calculation:
Let's say:
- Your Last Period Start Date was November 10, 2023.
- Your Average Period Length is 5 days.
- Your Average Cycle Length is 28 days.
Calculation:
- Estimated Next Period Start Date: November 10, 2023 + 28 days = December 8, 2023.
- Estimated Next Period End Date: December 8, 2023 + 5 days – 1 day = December 12, 2023.
Therefore, your estimated period would be from December 8, 2023, to December 12, 2023.
Important Considerations:
It's crucial to remember that this calculator provides an estimate. Menstrual cycles can be influenced by various factors, including:
- Stress
- Illness
- Changes in diet or exercise
- Travel
- Hormonal fluctuations
- Age
- Medical conditions (like PCOS or endometriosis)
For highly accurate tracking, especially if you are trying to conceive or manage a medical condition, consider using a dedicated period tracking app or consulting with a healthcare professional. They can help you understand your unique cycle patterns and identify any irregularities.
function calculatePeriod() {
var startDateInput = document.getElementById("lastPeriodStartDate");
var periodLengthInput = document.getElementById("averagePeriodLength");
var cycleLengthInput = document.getElementById("cycleLength");
var resultDisplay = document.getElementById("result").getElementsByTagName("p")[0];
var startDateStr = startDateInput.value;
var periodLength = parseInt(periodLengthInput.value);
var cycleLength = parseInt(cycleLengthInput.value);
// Validate inputs
if (isNaN(periodLength) || periodLength 31) {
resultDisplay.textContent = "Invalid period length. Please enter a number between 1 and 31.";
resultDisplay.style.color = "#dc3545"; /* Red for error */
return;
}
if (isNaN(cycleLength) || cycleLength 90) {
resultDisplay.textContent = "Invalid cycle length. Please enter a number between 1 and 90.";
resultDisplay.style.color = "#dc3545"; /* Red for error */
return;
}
if (startDateStr === "") {
resultDisplay.textContent = "Please select your last period start date.";
resultDisplay.style.color = "#dc3545″; /* Red for error */
return;
}
var startDate = new Date(startDateStr);
// Calculate next period start date
var nextPeriodStartDate = new Date(startDate);
nextPeriodStartDate.setDate(startDate.getDate() + cycleLength);
// Calculate next period end date
var nextPeriodEndDate = new Date(nextPeriodStartDate);
nextPeriodEndDate.setDate(nextPeriodStartDate.getDate() + periodLength – 1);
// Format dates for display
var options = { year: 'numeric', month: 'long', day: 'numeric' };
var formattedStartDate = nextPeriodStartDate.toLocaleDateString(undefined, options);
var formattedEndDate = nextPeriodEndDate.toLocaleDateString(undefined, options);
resultDisplay.textContent = formattedStartDate + " – " + formattedEndDate;
resultDisplay.style.color = "#28a745"; /* Success Green */
}