Pregnancy Toolkit
Free pregnancy calculators and trackers, from your first due date estimate through timing contractions. Nothing you enter leaves your device.
Dates and milestones
Due Date Calculator
Estimate your baby's due date from your last menstrual period, or work backward from a due date.
Pregnancy Week Calculator
Find out exactly how many weeks and days pregnant you are, with a progress bar and development milestones.
Trimester Calculator
See the exact date range for each trimester, which one you're in now, and what to expect.
Conception Date Calculator
Estimate your likely conception window from a due date, or forward from your last period.
Tracking
Planning ahead
About these tools
Pregnancy comes with a lot of date math. Due dates are counted from the first day of your last period rather than from conception, weeks don't line up neatly with months, and trimesters have specific boundaries. The date calculators here use the same standard conventions healthcare providers use, such as Naegele's rule for the due date, and explain the assumptions behind each result so you know what it can and can't tell you.
The kick counter and contraction timer are for the later weeks. Both keep their logs in your browser's local storage, so a page refresh won't lose your data and nothing is sent to a server. They're tracking tools, not diagnostic ones: if something feels wrong, such as a change in your baby's movements, contact your provider right away rather than relying on any app.
Every result here is an estimate based on averages. Your own provider's dates and advice always take precedence, especially if your due date has been set from an ultrasound. The guides explain the reasoning behind the numbers in more depth.
Guides
All guides →Aug 10, 2026
How your due date is actually calculated (and why it's an estimate, not a deadline)
What Naegele's rule actually does, why it assumes a 28-day cycle, and why most babies aren't born on their exact due date.
Sep 24, 2026
Pregnancy weeks to months: how the counting actually works
Why pregnancy is dated from your last period, how to read weeks and days, a weeks-to-months chart, and the official term definitions.
Aug 17, 2026
Kick counting: what's normal, and when to call your doctor
Why fetal movement counting is commonly recommended, one general method providers cite, and why a noticeable decrease in movement is always worth a prompt call.
Sep 24, 2026
Early term, full term, late term: what the definitions mean
The official definitions for preterm, early term, full term, late term, and post-term births, why they changed in 2013, and why the final weeks matter.