Pregnancy Calculators and Tools
PanaKit's pregnancy calculators help you date your pregnancy and plan the months after. Work out your due date from your last period, IVF transfer or scan, see how many weeks pregnant you are, check healthy weight gain, and plan breastfeeding calories and alcohol timing. Each tool is built on ACOG, NHS or CDC guidance and runs privately in your browser.
This hub grows as we add new PanaKit pregnancy tools.
Due date and pregnancy dating
- PregnancyPregnancy Due Date Calculator
Find your due date from your last period, conception date, IVF transfer or current week, or work back from a due date you already know.
- PregnancyGestational Age Calculator
See how far along you are in weeks and days from your last period, due date, scan or conception date, including corrected age for babies born early.
- PregnancyIVF Due Date Calculator
Get your IVF or frozen embryo transfer (FET) due date from your transfer date and embryo age, Day 3 or Day 5.
- PregnancyUltrasound Due Date Calculator
Turn your scan date and measured gestational age into a due date, and see whether the scan should change your period-based date.
Also useful
Weight and nutrition in pregnancy
Breastfeeding and postpartum
The CDC recommends about 330 to 400 extra calories a day for well-nourished breastfeeding mothers, and waiting at least 2 hours after a single drink before nursing. These tools personalise both.
- PregnancyBreastfeeding Calorie Calculator
Estimate the extra daily calories you need while breastfeeding from your weight, activity level and how often you nurse.
- PregnancyBreastfeeding Alcohol Calculator
See when alcohol should be out of your breast milk after a drink, in US standard drinks or UK units.
Which pregnancy calculator do I need?
| I want to know… | Use this | What you need |
|---|---|---|
| When my baby is due | Pregnancy Due Date Calculator | First day of your last period (or conception date) |
| How many weeks pregnant I am today | Gestational Age Calculator | Last period, due date or scan details |
| My due date after IVF or FET | IVF Due Date Calculator | Transfer date and embryo age (Day 3 or Day 5) |
| My due date from a dating scan | Ultrasound Due Date Calculator | Scan date and the gestational age on the report |
| When I conceived | Conception Date Calculator | Last period, due date or birth date |
| How much weight to gain | Pregnancy Weight Gain Calculator | Pre-pregnancy weight, height and current week |
| How much extra to eat while breastfeeding | Breastfeeding Calorie Calculator | Weight, activity and how often you nurse |
| When I can breastfeed after a drink | Breastfeeding Alcohol Calculator | Weight, drinks and when you started |
Frequently asked questions
Start with the Pregnancy Due Date Calculator and the first day of your last period. It gives your estimated due date and how many weeks pregnant you are. If you conceived through IVF, use the IVF Due Date Calculator instead. After your dating scan, check your date with the Ultrasound Due Date Calculator.
The standard method adds 280 days (40 weeks) to the first day of your last period. If you know your conception date, it adds 266 days to that instead. The NHS notes that pregnancy normally lasts 37 to 42 weeks, so your due date is a guide to when your baby may arrive, not a fixed date.
A calculator is only as accurate as the date you enter, and a date from your last period assumes ovulation around day 14. ACOG says an ultrasound in the first trimester, up to 13 weeks and 6 days, is the most accurate way to set or confirm your due date. After that, your due date should rarely change.
Gestational age is counted from the first day of your last period, about two weeks before conception usually happens. Fetal age counts from conception. So at "8 weeks pregnant" the embryo is about 6 weeks old. Doctors, midwives and scans all use gestational age.
ACOG says IVF due dates should come from the embryo's age and the transfer date. For a Day 5 embryo transfer, add 261 days to the transfer date. For a Day 3 transfer, add 263 days. Fresh and frozen transfers are dated the same way.
The CDC suggests waiting at least 2 hours after a single drink before nursing, and about 2 more hours for each extra drink. How long alcohol stays in your milk also depends on your weight and what you drank, which the Breastfeeding Alcohol Calculator works out for you.
Pregnancy guides
- GuideHow pregnancy due dates are calculated
- GuideHow can I calculate my due date of pregnancy?
- GuideHow many weeks pregnant am I?
- GuideGestational age vs fetal age
- GuideHow to calculate your FET due date
- GuidePregnancy weight gain: how much is healthy?
- GuideWhen was I conceived?
- GuideCan you ovulate while breastfeeding?
Sources: ACOG, Methods for Estimating the Due Date and Weight Gain During Pregnancy; NHS, Due date calculator and 12-week scan; CDC, Alcohol and breastfeeding and Maternal diet and breastfeeding.