learn.howToCalculate

learn.whatIsHeading

The fertility window is the 6-day period when conception is possible — 5 days before ovulation and ovulation day itself. Ovulation typically occurs 14 days before the next period.

공식

Ovulation typically day 14 of 28-day cycle (range 12–16). Fertile window: day 12–16 (5 days pre-ovulation, day of ovulation). Sperm viable 5 days; egg 12–24 hours.

CycleLength: Menstrual cycle length (Days (typical 28, range 21–35))
OvulationDay: Expected ovulation (Days from cycle start)
FertileWindow: Peak fertility window (Days (5–6 day window))

단계별 가이드

1Ovulation ≈ Cycle length − 14 days from LMP
2Fertile window = Ovulation − 5 days to Ovulation day
3Sperm survive 3–5 days; egg survives ~12–24 hours
4OPK tests and basal body temperature confirm ovulation

풀어진 예시

입력

30-day cycle, LMP 1 January

결과

Ovulation ≈ Jan 16; Fertile window: Jan 11–16

자주 묻는 질문

How do I predict ovulation?

Calendar method: ovulation = cycle length − 14 days (average). LH surge kits detect surge 24–36 hrs before ovulation (most accurate). Basal body temperature rise (0.5°C) confirms ovulation post-hoc.

Does cycle length variation matter?

Yes. 28-day cycles: simple prediction. 21–35 days normal but unpredictable. Track 3 months minimum to establish pattern. Apps (Clue, Flo) help predict best.

What decreases conception chances?

Irregular cycles, anovulation (no ovulation), poor egg/sperm quality, timing (intercourse every 2–3 days throughout cycle > precise timing), age (female fertility drops 35+).

계산할 준비가 되셨나요? 무료 Fertility Window 계산기를 사용해 보세요

직접 시도해 보세요 →