You can usually tell a baby’s sex between 10 and 20 weeks of pregnancy, depending on the test or scan used. The most common time is at the mid‑pregnancy ultrasound around 18–20 weeks.

When Can You Tell the Gender of a Baby?

Super quick overview

  • Earliest lab test (noninvasive blood test/NIPT): from about 10 weeks pregnant, very high accuracy (around 99%).
  • Typical ultrasound time: 18–22 weeks at the anatomy scan, when most parents find out; accuracy often above 95–97% if the baby’s position is good.
  • Invasive diagnostic tests (done for medical reasons):
    • Chorionic Villus Sampling (CVS): 10–13 weeks.
* Amniocentesis: **15–20 weeks**.
  • Very early specialized blood tests: some private labs offer sex determination as early as 6 weeks by detecting fetal DNA in the mother’s blood.

Main medical ways to know

1. Noninvasive blood tests

These look for fragments of the baby’s DNA in your blood.

  • NIPT (Non‑Invasive Prenatal Testing):
    • Usually offered from 10 weeks of pregnancy.
* Checks chromosomes for conditions (like trisomies) and can also reveal sex (presence or absence of Y chromosome).

* Often quoted as **about 99% accurate** for sex.
  • Early private gender blood tests:
    • Some services say they can tell sex from 6 weeks using highly sensitive lab methods to detect Y‑chromosome DNA.
* Marketed as up to **99.9% accurate** when done correctly, though they’re usually not part of routine medical care.

Think of these as reading tiny “genetic footprints” in your bloodstream long before an ultrasound can see anything clearly.

2. Ultrasound

Ultrasound is the classic moment many parents picture.

  • When genitals become visible:
    • External genitals start forming around week 7 , but they’re hard to distinguish until about week 14 or later.
  • Early gender guesses:
    • Some providers may attempt a guess around 14–16 weeks , but accuracy is lower, and it depends a lot on baby’s position and image clarity.
  • Standard anatomy scan:
    • Typically done between 18 and 22 weeks.
* This is when **most parents** find out, if they want to.

* Accuracy for sex at this point is often **around 95–99%** , again depending on baby’s position and the person doing the scan.

* Primary purpose is to check overall growth and anatomy; sex is a bonus.

3. Diagnostic procedures (with risks)

These are not done just to find out the gender; they are ordered for medical reasons (for example, increased risk of genetic conditions).

  • Chorionic Villus Sampling (CVS):
    • Usually between 10 and 13/14 weeks.
* Uses placental tissue to examine chromosomes, which also reveal sex.

* Accuracy for sex is very high (around **98%**), but sometimes results can be unclear.

* Carries a small risk of miscarriage, so it’s reserved for higher‑risk pregnancies.
  • Amniocentesis:
    • Usually between 15 and 20 weeks.
* Tests amniotic fluid for genetic information, also identifying sex very accurately.

* Also carries a small risk of complications, so again, used for medical indications—not just curiosity.

Fun methods vs real science

You’ll see a lot of “gender prediction” buzz online and in forums in 2025–2026—quizzes, ring tests, Chinese gender calendars, craving‑based predictions, and bump‑shape theories.

  • Old wives’ tales & prediction quizzes:
    • Things like “carrying high = girl, low = boy” or “sweet cravings = girl” are fun but not reliable.
  • At‑home tests sold as “gender kits”:
    • Some may use urine or unvalidated methods; they’re more like novelty products and can be wrong.

Enjoy these as light entertainment, but don’t plan names, nurseries, or big reveals around them alone.

Timeline snapshot (for quick planning)

[1] [10][7][5] [5][1] [7][5] [3][7][5] [7][1][5]
Method Earliest typical week Why/when it’s used Notes on accuracy & risk
Private early blood gender test ~6 weeks Elective, early curiosity Up to ~99–99.9% accuracy claimed if done correctly; noninvasive.
NIPT (noninvasive blood test) 10 weeks Primarily to screen for chromosomal conditions; sex result is optional bonus About 99% accurate for sex; simple blood draw, no risk to baby.
CVS 10–13 weeks High‑risk pregnancies needing genetic diagnosis ~98% accurate for sex; small risk of miscarriage, not used just for gender.
Early ultrasound guess 14–16 weeks Sometimes offered as an “early peek” Accuracy lower; depends on fetal position and experience of sonographer.
Standard anatomy ultrasound 18–22 weeks Routine scan to check baby’s development; many find out sex now Accuracy often 95–99% if baby’s position is favorable; no risk to baby.
Amniocentesis 15–20 weeks Genetic diagnosis in higher‑risk pregnancies Very accurate for sex, but carries small miscarriage risk; only for medical reasons.

Today’s “trending” angle

Right now, many parents discuss a mix of science and fun on forums: they might do a 10‑week NIPT for medical reassurance and gender, then still play with ring tests, Chinese calendars, and social‑media “nub theory” ultrasound guesses around 12–14 weeks.

But across medical sources, the consistent message in 2025–2026 is:

  • If you want the earliest accurate and low‑risk option, talk to your provider about NIPT around 10 weeks.
  • If you’re fine waiting for the classic moment, expect to find out at your 18–20‑week anatomy ultrasound.

Bottom line:
You can first reliably find out your baby’s sex via a medical blood test around 10 weeks , and most people learn it at the 18–20‑week ultrasound , while very early private blood tests may offer answers from 6 weeks onward.

Information gathered from public forums or data available on the internet and portrayed here.