How long is the luteal phase?
The luteal phase usually lasts 12 to 14 days, and anywhere from about 10 to 17 days is considered normal. It runs from the day after ovulation to the day before your period. In a study of over 600,000 cycles, the average was 12.4 days. A luteal phase shorter than 10 days is called short.
Normal luteal phase length
| Length | What it means |
|---|---|
| Under 10 days | Short luteal phase; may make it harder to get pregnant |
| 10 to 11 days | Normal, on the short side |
| 12 to 14 days | Most common |
| 15 to 17 days | Normal, on the long side |
| 18 days or more after ovulation, no period | Possible pregnancy; take a test |
The luteal phase is steadier than the follicular phase before it. In the large app-based study, the follicular phase varied from about 10 to 30 days, while most luteal phases fell between about 7 and 17 days. That's why most of the change in your cycle length comes from when you ovulate, not from the luteal phase.
How to measure your luteal phase
- Pin down your ovulation day using LH tests, a temperature rise, or a retrospective estimate from a wearable.
- Count the days from the day after ovulation up to the day before your next period.
- Repeat for two or three cycles; your luteal phase is usually within a day or two each time.
- Or use our luteal phase calculator.
Basal body temperature is a handy tool here: it rises after ovulation and stays up until your period, so the number of high-temperature days roughly equals your luteal phase.
What a short luteal phase can mean
A luteal phase under 10 days may not give the uterine lining enough time to support implantation, so it can matter if you're trying to conceive. It's sometimes linked to thyroid problems, high prolactin, PCOS, intense exercise, under-eating, perimenopause or simply a one-off cycle. Read more in short luteal phase.
Why luteal phase length matters for mood
The luteal phase is where PMS lives. Knowing it lasts, say, 13 days for you means you know roughly when the harder days arrive and when relief comes. See what is the luteal phase and the pillar guide to the luteal phase.
See a doctor if your luteal phase is regularly under 10 days and you're trying to conceive, if you spot for several days before every period, or if you've been trying to get pregnant for 12 months (6 months if you're 35 or older).
Frequently asked questions
Can the luteal phase be 16 days?
Yes, 16 days is within the normal range. If it's unusually long for you and you could be pregnant, take a test.
Does the luteal phase change with age?
It's fairly stable through adulthood, though it can become shorter or less regular in perimenopause.
Can you lengthen a short luteal phase?
Treating an underlying cause, like thyroid problems or under-eating, can help. A doctor can advise if you're trying to conceive.
Is luteal phase the same as PMS?
No. Everyone who ovulates has a luteal phase. PMS is the symptoms some people feel in its last days.
Sources
- Cleveland Clinic: Luteal phase
- Bull JR et al. Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles. npj Digital Medicine (2019)
- Cleveland Clinic: Basal body temperature
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
Keep reading
Luteal phase calculator: how long is my luteal phase?Free luteal phase calculator: enter your ovulation day and next period to see your luteal phase length and whether it sits in the typical 11 to 17 day range.
What is the luteal phase?What is the luteal phase? The part of your cycle from ovulation to your period, when progesterone rises and PMS happens. A plain explanation in 2 minutes.Luteal phase: why feelings get louderWhat the luteal phase is, how long it lasts, why progesterone rises and falls, and the common symptoms: PMS, cravings, low energy and mood changes.
What is a short luteal phase, and does it matter?A short luteal phase is 10 days or fewer from ovulation to period. What causes it, what the research says about fertility, and when to see a doctor.
How long is each phase of the menstrual cycle?How long each phase of the menstrual cycle lasts: period, follicular, ovulation and luteal phase lengths, what's normal, and why your cycle length changes.