Age in Weeks

Enter your date of birth to instantly see your age in weeks. This counter updates live (every second) for free.

Live total plus an exact breakdown from your birth date.


Tip: include the time for ultra-accurate seconds.
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Your age in weeks
Live total + exact breakdown
Time lived on Earth
Peter Drucker — “Time is the scarcest resource, and unless it is managed, nothing else can be managed.”
FAQ

Is this accurate? It’s accurate to the second based on your device time and time zone.

What if I don’t know my birth time? Leave it at 00:00 — your age still works great.

Can I share my result? Yes. The share link includes your settings.

Try the other tools: Age CalculatorBirthday CountdownAge in SecondsAge in Days

Age in Weeks — A Healthcare-Focused Perspective

Why Weeks Are Critical in Healthcare

Calculating age in weeks is essential in medical and developmental contexts. Weeks strike the ideal balance between precision and readability — detailed enough for clinical accuracy, yet simple enough for consistent use. This is why weeks are the preferred unit of time across much of healthcare.

In situations where rapid physical and neurological changes occur, measuring time in years is too imprecise, while days can be unnecessarily granular. Weeks provide the clarity clinicians need to make informed, timely decisions.

Pregnancy and Infant Development

In obstetrics and pediatrics, age in weeks is the standard because development progresses quickly and predictably:

  • Pregnancy is measured week by week, with each stage associated with specific fetal developments and clinical expectations
  • Infant growth milestones — such as weight gain, motor skills, and feeding patterns — are tracked in weekly intervals
  • Vaccination schedules depend on defined weekly age ranges to ensure safety and effectiveness

During early development, a difference of even a few weeks can be medically significant. Accurate age measurement helps healthcare providers align care with the child’s actual developmental stage rather than an approximate calendar age.

Developmental and Pediatric Standards

Healthcare professionals rely on age in weeks to:

  • Assess developmental progress against established medical benchmarks
  • Identify growth or developmental concerns early, when intervention is most effective
  • Apply standardized clinical guidelines accurately, ensuring consistent care across patients

Using weeks ensures that evaluations, treatments, and recommendations are based on precise developmental timing. This consistency improves outcomes and reduces risk, particularly during the most vulnerable stages of life.

Age in weeks isn’t about precision for its own sake. It’s about safety, accuracy, and delivering the right care at the right time.