ovuLivo

Ovulation calculator

Know your fertile days

Your last period + your cycle length = your ovulation day and fertile window, mapped on a calendar.

1 · Your cycle

Two fields are all we need to predict your window.

Next period
—

2 · Your fertile window

Updated live. The most fertile days are marked in amber.

Fertile window
—
5 days before to 1 day after ovulation
Most fertile
—
Day before ovulation + ovulation day
Ovulation day
—
Egg released, ~24h egg life

3 · Your cycle calendar

—
SunMonTueWedThuFriSat
Period Fertile Most fertile

Confirm with BBT

Track your morning temperature

A sustained rise of about 0.3–0.5°C confirms ovulation happened. Enter your basal body temperatures below; the day of the rise is marked green.

Temperatures by cycle day

Take them at the same time each morning, before getting up. Leave unknown days blank.

Cycle dayTemp (°C)

Best timing

How to time the fertile window

Before the window

  • Aim to let 2–3 days pass without intimate time before the fertile window so sperm quality stays high.

Sperm live 3–5 days inside; the egg lives about 24 hours.

During it

  • Intimate every 1–2 days through the fertile window.
  • Focus around the most fertile days for best odds.

Every-other-day timing captures the window almost as well as daily.

After ovulation

  • Once temperature confirms a sustained rise, the fertile window has passed.
  • Rest — the next cycle will repeat with a fresh window.

Prediction tools underestimate when cycles are irregular.

A quick way to estimate your most fertile days

If you are trying to conceive or simply want to understand your cycle better, ovuLivo gives you a straightforward estimate of when ovulation is likely to occur. Enter the first day of your last period along with your average cycle length, and the calculator projects your fertile window and expected ovulation date. It is designed for anyone who prefers a no-signup, instant answer rather than tracking multiple symptoms over weeks. Use it as a starting point for planning intercourse, scheduling conversations with a healthcare provider, or confirming patterns you have already noticed.

Getting your fertile window in seconds

  1. Enter the first day of your most recent period using the date field provided.
  2. Type your average menstrual cycle length in days, if different from the default.
  3. Review the estimated ovulation date and fertile window range shown on screen.
  4. Copy or screenshot the results so you can compare them next month.
  5. Repeat with updated dates each cycle to spot consistent patterns over time.

Frequently Asked Questions

How does the ovulation calculator work?

Enter the first day of your last period and your average cycle length. The tool estimates your ovulation day and fertile window from those two numbers.

Which days are the most fertile?

Ovulation is estimated about 14 days before your next period begins, and the fertile window is the five days leading up to it plus the day itself.

Can I use it alongside temperature tracking?

Yes. The fertile-window view is designed to be read together with morning basal body temperature and other cycle signs.

Is the ovulation calculator private?

Yes. Everything runs in your browser and your cycle dates are never uploaded or stored.

Latest Articles

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Before we get into anything else: set a daily alarm for the same early morning time, including weekends.