Home
Health Tools
Ovulation Calculator

Health Tools

Ovulation Calculator

Calculate your fertile window and ovulation date. Find the best time to conceive with our accurate fertility calculator.

100% Private Instant Results Visual Calendar Fertility Tracking

Track Your Fertility

Last Period Start

Cycle Length (days)

Ovulation Date

Fertile Window

Your Most Fertile Days

Best time to conceive

Fertility Calendar

Period

Fertile Days

Ovulation

About Ovulation

Ovulation occurs 14 days before your next period. The fertile window includes the 5 days before and the day of ovulation. Sperm can survive up to 5 days, but the egg only 12-24 hours.

All calculations run locally. Your data stays private and never leaves your device.

How to Use

Enter Last Period

Select the first day of your last period

Enter Cycle Length

Average cycle length (21-35 days)

Click Calculate

See your fertile window instantly

Track Calendar

View color-coded fertility days

Features

Instant Results

Get calculations in real-time

100% Private

No data ever leaves your device

Visual Calendar

Color-coded fertility tracking

Fertile Window

6-day fertility window

Cycle Guide

21-24 daysOvulation day 7-10

25-30 daysOvulation day 11-16

31-35 daysOvulation day 17-21

Egg Viability12-24 hours

Sperm ViabilityUp to 5 days

Why Use Our Ovulation Calculator?

Instant Results

Get your fertile window in milliseconds

100% Private

Your cycle data never leaves your device

Visual Calendar

Color-coded fertility tracking

Accurate Prediction

Based on standard ovulation timing

Frequently Asked Questions

What is ovulation?

Ovulation is when a mature egg is released from the ovary. It's the most fertile time of your cycle and occurs about 14 days before your next period.

How long is the fertile window?

The fertile window is 6 days: the 5 days before ovulation and the day of ovulation. This is when you're most likely to conceive.

How accurate is this calculator?

This calculator provides estimates based on average cycle lengths. For irregular cycles, results may vary. Track multiple cycles for better accuracy.

What is a normal cycle length?

Normal menstrual cycles range from 21 to 35 days. The average is 28 days. Cycles outside this range should be discussed with a healthcare provider.

Can I get pregnant outside fertile window?

While possible, the chances are significantly lower. The fertile window is when conception is most likely to occur due to sperm and egg viability.

Is my data private?

Yes! All calculations happen in your browser. We never store or transmit any personal information.

Related Health Tools