Àwọn Àwọn Àkọ́lé

Predict your next few periods, ovulation and fertile window from your last period.

Àwọn ààyè-iṣẹ́ ìtàn

Ìgbà ìparí ìjánu-ìjánú

days

Ìgbà ìjánú ?

days

Ìgbà wò nínú àwọn ọjọ́ tí ò fi pẹ́.

Àwọn ìṣàmúlò-ètò láti fi hàn

Àwọn ààyè-iṣẹ́ ìtàn —

Àwọn ìgbà láti ààyè-iṣẹ́ —

Ìjánu-ìṣàmúlò-ètò tókàn —

Fèrèsé àìdá —

Àwọn Àtòjọ-ẹ̀yàn àwọn ìṣàmúlò-ètò

Ńlà àwọn àwọn ààtò àtòjọ-ẹ̀yàn yìí?

Àkóónú ìṣàmúlò-ètò yìí

A period calculator predicts when your next several periods are due from the first day of your last period and your average cycle length. Counting forward one cycle length gives each period start; ovulation falls about 14 days before the next period, and the fertile window is the five days before ovulation plus the day itself. It also lays out a schedule of upcoming cycles with their period, ovulation and fertile dates.

On a 28-day cycle, your next period is due 28 days after the last one began, the one after that at 56 days, and so on for as many cycles as you ask it to show. Ovulation for each cycle is placed 14 days before that period start, with the fertile window running the five days before it. Enter a longer or shorter average and every projected date shifts by the same amount.

Use it to know when to expect your period over the coming months, to plan around it, or to see your fertile days alongside each cycle. Set your usual period length so the schedule shows start and end dates. Real cycles vary by a few days month to month with stress, illness and hormones, so the predictions are estimates; a consistently missed period is worth a pregnancy test or a clinician’s advice.

Àwọn Àtòjọ-ẹ̀yàn

Bawo ní o ṣe lè sọ̀rọ̀ pé mò tí ìgbà ìsẹ́ mì tí a tì ṣẹ́lẹ̀?

Àwọn ìṣàmúlò-ètò ní gbogbo wọn ní ìgbà ìtàn ìtàn kan láti inú àwọn ìtàn tí a tì kọ́, láti jẹ́ pé àtòjọ-ẹ̀yàn náà ń fi ìtàn ìtàn rẹ̀ (28 ọjọ̀ nípa ìpéwọ̀n) sí ọjọ́ akọkọ tí àwọn ìtàn rẹ̀ tí a tì kọ́, àtí ìṣàmúlò-ètò náà láti fi àwọn oṣù àwọn mìíràn tí a tì gbọ́.

Ìgbà wo nínú àwọn àwọn ààtò àwọn ààtò àwọn ààtò àwọn ààtò àwọn ààtò àwọn ààtò àwọn ààtò àwọn ààtò àwọn ààtò àwọn ààtò

Ò ǹyàn àwọn ìṣàmúlò-ètò ìtàn tí a tí fi àwọn ìṣàmúlò-ètò àìdájú. Àwọn ìṣàmúlò-ètò ìṣàmúlò-ètò tí a tì fi pamọ́ nípa àwọn ọjọ̀ àwọn ààyè - àti àwọn ìṣàmúlò-ètò àti àwọn ìṣàmúlò-ètò àwọn ìṣàmúlò-ètò - láti jẹ́ àwọn ààyè bí àwọn à

Kini tí mò bá jẹ́ pé àwọn ìṣàmúlò-ètò mì kò ní ìṣàmúlò-ètò?

Fi àwọn ìṣàmúlò-ètò inú àwọn ààtò àwọn ìṣàmúlò-ètò rẹ̀ sínú ìgbà ìṣàmúlò-ètò tí o fẹ́, àwọn ìṣàmúlò-ètò náà ó ní ìdáràn. Àwọn ìṣàmúlò-ètò àwọn ìṣàmúlò-ètò àwọn àwọn ìṣàmúlò-ètò àwọn àwọn ìṣàmúlò-ètò àwọn

Ìgbà wò nínú àwọn ààyè-iṣẹ́ mìíràn mìí

Ó jẹ́ ìgbà ìgbà ìṣàfarawégbè kan láti àwọn ìṣàmúlò-ètò rẹ̀ tí wọ́n tí bẹrẹ, bẹ́ẹ̀ nínú ìṣàmúlò-ètò ọjọ́ 28, ìṣàmúlò-ètò tókàn rẹ̀ ní ọjọ́ 28 láti àwọn ìṣàmúlò-ètò tí wọ́n tí bẹrẹ. Àtòjọ-ẹ̀yàn náà ń fi àwọn oṣù kọ̀ǹpútà láti lò àwọn ìṣàmúlò-ètò ìpele-ìpilẹ̀ tí o fi pamọ́.

Bawo ni mo ṣe lè fi àwọn ìṣàmúlò-ètò mì pamọ́?

Log the first day of each period for a few months, then average the gaps between them. Entering that average gives more accurate predictions than assuming a fixed 28-day cycle.

Ńtí àtòjọ-ẹ̀yàn yìí lè ṣàfihàn àwọn ọjọ́ tí mò tí ìgbà ìṣàfarawé kọ̀ǹpútà?

Ya. Nínú àwọn àkókò tí a tí sọ̀rọ̀ ní gbogbo wọn, ò fi àwọn àwọn ààyè tí a tí sọ́rọ̀ ní ọjọ́ tí a tí ǹṣé ìjádé, ní àwọn ọjọ́ 14 nínú ìjádé tókàn, àti àwọn fèrèsé ọjọ́ mẹ́tà tí a tí ǹpa nínú wọn.

API — ló àwọn ìṣàmúlò-ètò yìí láti inú ìṣàmúlò-ètò

Fi àwọn ìṣàmúlò-ètò yìí kọ̀ǹpútà yìí láti jẹ́ ààyè-iṣẹ́ JSON tí a tí fi pamọ́ - kò ní bọ́tìnì kan tí a fẹ́. Fi àwọn fálù ààyè-iṣẹ́ sílẹ̀ sí bí àwọn àwọn ìṣàmúlò-ètò àti JSON. Anything you omit uses the same default this page is pre-filled with; an unknown parameter is a 400, never a silent zero. Ka àwọn àkọlé API kíkún →

Àwọn Ààyè Ìjánu-ìṣàmúlò-ètò

GET https://calculator.free/api/v1/period/

curl

curl "https://calculator.free/api/v1/period/?lmp=2026-08-09&cycle=28"

JavaScript `fetch()`

const r = await fetch(
  "https://calculator.free/api/v1/period/?" + new URLSearchParams({
    "lmp": "2026-08-09",
    "cycle": "28"
  }));
const data = await r.json();
console.log(data.results);

Results are estimates for general guidance only, not financial, medical or tax advice.

Àkóónú ìṣàmúlò-ètò yìí

Àwọn Àtòjọ-ẹ̀yàn

Àwọn Ìṣàmúlò-ètò Ìṣàmúlò-ètò

Àwọn Ààyè Ìjánu-ìṣàmúlò-ètò

curl

JavaScript fetch()

JavaScript `fetch()`