Due Date Calculator - Pregnancy
Estimate your pregnancy due date — from your last period or your IVF embryo transfer date (Day 3, 5, or 6), with gestational age and trimester.
Tool Interface
How to use
- From last period: enter the first day of your last menstrual period and your average cycle length, then calculate. Uses the standard 280-day (40-week) method, adjusted for your cycle.
- From IVF transfer: enter your embryo transfer date and the embryo's age at transfer (Day 3, 5, or 6), then calculate. Uses the clinical formula: transfer date + 266 days − embryo age.
- See your estimated due date plus how far along you are today, your trimester, and the estimated conception date.
- Everything runs in your browser — no signup, nothing uploaded.
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About This Tool
Introduction: When Is Your Baby Due?
Trencada's free Due Date Calculator estimates your delivery date two ways: from the first day of your last menstrual period (the standard 280-day method, adjusted for your cycle length), or from your IVF embryo transfer date using the clinical formula fertility clinics use (transfer date + 266 days − embryo age). You will also see how far along you are today, your trimester, and the estimated conception date.
How to Use the Due Date Calculator
- From last period: enter the first day of your last menstrual period and your average cycle length.
- From IVF transfer: enter your embryo transfer date and the embryo's age at transfer — Day 3, Day 5, or Day 6. Fresh and frozen transfers use the same formula.
- Press Calculate due date for your estimated due date plus gestational age, trimester, and conception estimate.
Key Features
- Two methods: last menstrual period or IVF embryo transfer dating
- IVF formula: the clinical standard — transfer date + 266 days − embryo age (Day 3: +263, Day 5: +261, Day 6: +260)
- Cycle adjustment: LMP method adapts to your average cycle length
- Full picture: due date, weeks + days along, trimester, conception estimate, days to go
- 100% private: your dates are calculated in your browser and never uploaded
Why Choose Trencada
Every Trencada tool is free forever with no accounts, no installation, and no hidden costs. The Due Date Calculator runs 100% in your browser — your personal dates never leave your device.
Frequently Asked Questions
How is an IVF due date calculated?
Fertility clinics use: due date = transfer date + 266 days − embryo age in days. A Day 5 blastocyst transfer adds 261 days; Day 3 adds 263 days; Day 6 adds 260 days. Fresh and frozen transfers use the same math.
How accurate is the estimate?
Only about 5% of babies arrive exactly on their due date — treat it as a planning guide. IVF dates are among the most reliable because the embryo's age is known exactly.
Is this medical advice?
No. This tool is for informational purposes only. Confirm your due date with your doctor or midwife, especially after fertility treatment.
Is my information private?
Yes. Everything is calculated locally in your browser — nothing you enter is uploaded, stored, or tracked.