Your pregnancy journey, supported at every step

Free, NHS-aligned pregnancy calculators and guides for UK parents. Calculate your due date, track your baby's growth, and prepare with confidence.

Calculate My Due Date
🔒 No data stored📋 No registration✅ Always free🏥 NHS-aligned🇬🇧 UK-based team

Due Date Calculator

5 methods: Last Period, Conception Date, How Far Along, Ultrasound, and IVF Transfer

Enter the first day of your last period to calculate your due date using Naegele's rule.

The first day of your last menstrual period
21 to 45 days (default 28)
12 to 16 days (default 14)

All pregnancy tools and guides

Everything you need throughout your pregnancy, all in one place.

Due Date Calculator

Calculate your estimated due date using your last period, conception date, ultrasound, or IVF transfer.

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Ovulation Calculator

Find your fertile window and peak ovulation day based on your cycle length.

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Weight Gain Calculator

Check recommended pregnancy weight gain based on NHS guidelines and your pre-pregnancy BMI.

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Week by Week Guide

Follow your baby's development from week 4 to week 40 with size comparisons and tips.

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Pregnancy Symptoms

Understand common pregnancy symptoms, when to expect them, and how to manage them.

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NHS Antenatal Appointments

A clear timeline of all your NHS midwife and scan appointments throughout pregnancy.

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Birth Plan Template

Create your personalised birth plan with our interactive UK checklist.

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After Birth Guide

What to expect in the weeks after birth, including postnatal care and newborn checks.

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Your pregnancy trimesters

Pregnancy is divided into three trimesters, each with its own milestones.

Weeks 1 to 12

First Trimester

  • Baby's organs begin forming
  • Morning sickness is common
  • Dating scan at 10 to 14 weeks
Weeks 13 to 27

Second Trimester

  • Baby starts moving (around week 18 to 20)
  • Anomaly scan at 18 to 21 weeks
  • Many parents feel most comfortable
Weeks 28 to 40

Third Trimester

  • Baby gains weight rapidly
  • Appointments become more frequent
  • Time to prepare your birth plan

Built for UK parents, not for profit

No data stored

All calculations run in your browser. Nothing is sent to our servers.

NHS-aligned

Our tools use methods and guidance consistent with NHS practice.

WCAG 2.1 AA

Designed to be fully accessible with screen readers and keyboard navigation.

No adverts ever

No advertising, no tracking, no sponsored content. Ever.

Explore our pregnancy resources

Due Date Calculator →Ovulation Calculator →Weight Gain Calculator →Week by Week Guide →Pregnancy Symptoms →NHS Antenatal Appointments →Birth Plan Template →After Birth Guide →

Frequently asked questions

How accurate is a pregnancy calculator?
Pregnancy calculators provide an estimate based on your last menstrual period (LMP) or conception date. Only about 4% of babies are born on their exact due date. Your NHS dating scan (offered at 10 to 14 weeks) is the most accurate way to confirm your dates.
How is my due date calculated?
Most due dates are calculated using Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period. Our calculator also adjusts for non-standard cycle lengths. Your NHS dating scan may revise this estimate based on your baby's measurements.
What is a normal pregnancy length in the UK?
A full-term pregnancy lasts between 37 and 42 weeks. Your estimated due date is at 40 weeks, but it is perfectly normal to deliver anywhere between 37 and 42 weeks. The NHS offers induction from 41 to 42 weeks if labour has not started naturally.
Does the calculator store my data?
No. All calculations happen entirely in your browser. We do not collect, store, or transmit any information you enter into our calculators. Your pregnancy data stays completely private.