Àwọn Àwọn Àkọ́lé

Estimate the date of conception from a due date or your last menstrual period.

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Àwọn ààtò àwọn ìṣàmúlò-ètò

Àwọn ààyè-iṣẹ́ ìtàn

Ìgbà ìparí ìjánu-ìjánú ?

days

Adjusts ovulation timing when working from your last period.

Àwọn ààyè-iṣẹ́ ìṣàmúlò-ètò —

Àwọn ìṣàmúlò-ètò àwọn ìṣàmúlò-ètò —

Àwọn ààtò àtòjọ-ẹ̀yàn —

Àwọn ìṣàmúlò-ètò —

Àwọn Àtòjọ-ẹ̀yàn àwọn ìṣàmúlò-ètò

Ńlà àwọn àwọn ààtò àtòjọ-ẹ̀yàn yìí?

Àkóónú ìṣàmúlò-ètò yìí

A conception calculator estimates when conception likely occurred. From a due date it counts back 266 days (38 weeks), because fertilization happens about two weeks after the last period on a standard 28-day cycle and pregnancy runs 280 days from that period. From a last-period date it counts forward to ovulation (cycle length minus 14 days). Because sperm survive several days, a likely conception range is shown around the central date.

Working from a due date, subtract 266 days: a due date of, say, 40 weeks out places conception 38 weeks earlier, with the last period roughly two weeks before that (due date minus 280 days). Working from your last period, it adds cycle length minus 14 to find ovulation — day 14 on a 28-day cycle, day 16 on a 30-day cycle. It then shows today’s gestational age, measured from the last period rather than conception.

Use it to trace back roughly when a pregnancy began, either out of curiosity or to line up dates with a due date. The several-day range reflects that sperm can survive up to about five days, so conception may follow intercourse by a few days. Actual ovulation varies, so an early dating ultrasound is the most reliable check; this tool is for information, not medical advice.

Àwọn Àtòjọ-ẹ̀yàn

Bawo ni a ṣe le ṣe ayẹwo ifẹnufẹ lati ọjọ ti o yẹ?

A due date is 280 days (40 weeks) after the last menstrual period, and conception occurs about 14 days after that period. So conception is roughly the due date minus 266 days (38 weeks).

Kini idi ti a fi fi àwọn ààyè-iṣẹ́ ìṣàfarawé kọ̀ǹpútà hàn, àti àwọn ààyè-iṣẹ́ àwọn ìṣàmúlò-ètò?

Sperm can survive up to about five days in the reproductive tract, so intercourse a few days before ovulation can still cause pregnancy. The range spans that fertile window around the estimated ovulation day.

Ńwó ní ọjọ́ ìgbàgbọ́ náà jẹ́ kanna bí ọjọ́ ìgbàgbọ́?

Kò yẹ. Ìgbà tí a bá fi gbọ́dọ̀ gbọ́dọ̀ (ìgbà tí a bá fi gbọ́dọ̀ gbọ́dọ̀) nígbà tí a bá gbọ́dọ̀ gbọ

Njẹ mo ti gba ọmọ ti mo ba mọ ọjọ́ ti mo ti fẹ́?

Fi àwọn ọjọ 266 (ọjọ 38) kuro nínú àwọn ọjọ́ tí a fi ṣẹ́lẹ̀. Nítorí àwọn ayẹyẹ́ nínú ẹ̀yàn náà jẹ́ ọjọ́ 280 láti inú àkókò tókàn àti àkókò nínú ọjọ́ 14 láti inú rẹ̀, àkókò náà tí ìgbà àwọn ọsẹ meji láti inú àkókò náà.

Lé kàn kálẹ̀ndà ìṣàfarawé ìṣàfarawé sọ mì pé ẹnítí babà náà jẹ́?

Only loosely. It gives a likely conception date and a several-day window around ovulation, but because sperm survive several days, paternity cannot be settled from dates alone and needs a DNA test.

Kini idi ti a fi n ṣe ayẹyẹ ni ọsẹ meji sẹyin?

Pregnancy is dated from the first day of the last period for convenience, yet fertilisation happens at ovulation about two weeks later. That is why the gestational age this tool shows is roughly two weeks more than the time since conception.

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/conception/

curl

curl "https://calculator.free/api/v1/conception/?mode=due&due=2027-01-06&lmp=2026-08-09"

JavaScript `fetch()`

const r = await fetch(
  "https://calculator.free/api/v1/conception/?" + new URLSearchParams({
    "mode": "due",
    "due": "2027-01-06",
    "lmp": "2026-08-09"
  }));
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()`