Why Track Your Cycle?
Your menstrual cycle is a vital sign of your overall health. Tracking it does more than just tell you when to buy tampons.
Health Insights
A regular cycle suggests your hormones are balanced. Irregularities can be the first sign of stress, thyroid issues, or conditions like PCOS. Knowing your rhythm helps you plan vacations, workouts, and big events around your energy levels.
Predict Mood Changes
Know when PMS might strike so you can be kinder to yourself.
Family Planning
Crucial for both trying to conceive and natural birth control methods.
Understand Cravings
Hormonal shifts in the Luteal phase often trigger hunger. Knowing this helps you manage diet.
Calendar View
See a 3-month projection of your cycle, including period days, fertile window, and PMS days.
Custom Settings
Adjust cycle length and period duration. Not everyone is a "standard 28 days".
No Tracking App
No need to download an app that sells your data. Calculate instantly in your browser.
Why Use This Tool?
Data Privacy
Your cycle data is personal. We do not store, save, or share your period dates.
Symptom Prediction
We highlight the days you are likely to feel cramps or mood swings so you can prepare.
Visual Planning
A clear, color-coded calendar makes it easy to see your month at a glance.
How to Use the Period Calculator
Get your personalized calendar in seconds.
Select Last Period Date
Choose the *first day* your last period started. This is Day 1 of your current cycle.
Set Cycle Length
Enter the average number of days between your periods (e.g., 28 days). Also, set how long your period usually lasts (e.g., 5 days).
Get Your Calendar
View predictions for your next 3 months, including fertile windows, ovulation days, and estimated PMS start dates.
Calculate Your Cycle
Enter your details below.
Decoding Your Cycle
What actually happens during those 28 days?
1. Menstruation (Days 1-5)
The uterus lining sheds. Estrogen and progesterone are at their lowest levels, which can cause low energy and cramps.
2. Follicular Phase (Days 6-14)
Estrogen rises, boosting energy and mood. An egg prepares to be released. This is often when you feel your best.
3. Ovulation (Day 14)
The egg is released. You are at peak fertility. You might notice a rise in body temperature and clearer skin.
4. Luteal Phase (Days 15-28)
Progesterone rises. If not pregnant, PMS symptoms (bloating, mood swings, cravings) may start appearing in the week before your period.
Healthy Cycle Tips
Eat Iron-Rich Foods
Replenish iron lost during menstruation with leafy greens, red meat, or fortified cereals to fight fatigue.
Hydrate for PMS
Drinking more water actually reduces water retention and bloating during your Luteal phase.
Prioritize Sleep
Your body works harder during your period. Aim for 8 hours to help regulate hormones and mood.
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Frequently Asked Questions
Is my cycle irregular?
A "regular" cycle is anywhere from 21 to 35 days. Variations of a few days each month are normal. If your cycle varies by more than 7-9 days, it is considered irregular.
Can I get pregnant on my period?
It is unlikely but possible, especially if you have a short cycle (e.g., 21 days). Sperm can live for 5 days, so if you ovulate early, intercourse during menstruation could lead to conception.
How accurate is this calculator?
It is a mathematical prediction based on averages. Stress, illness, or travel can delay ovulation and your period. It is great for planning but should not be used as strict birth control.
What are "Safe Days"?
These are days outside your fertile window (usually right before and right after your period) where the risk of pregnancy is lowest. However, no day is 100% guaranteed safe without protection.