OB Wheel — Pregnancy Due-Date Calculator

OB Wheel brings the precision of clinical pregnancy dating tools to your iPhone, iPad, and Mac. Whether you’re an obstetrician, midwife, nurse, medical student, or expectant parent, OB Wheel provides accurate, evidence-based pregnancy calculations following ACOG Committee Opinion guidelines.

Accurate Pregnancy Calculations

Calculate due dates using any standard dating method:

• Last Menstrual Period (LMP) — the standard clinical approach
• Conception or Ovulation Date — for those who track their cycle
• Ultrasound Dating — with ACOG-compliant redating thresholds
• IVF/ART — embryo transfer support for Day 3, 5, or 6
• Known Due Date — reverse calculation from EDD

Comprehensive Pregnancy Information

Every calculation provides a complete clinical picture:

• Estimated Due Date with countdown
• Current gestational age in weeks and days
• Trimester milestones (13w, 27w, 39w)
• Expected fetal size and weight
• Full term date (39 weeks)
• Interactive OB Wheel visualization

Patient Management

Keep track of multiple pregnancies with built-in patient records:

• Save patients with pregnancy records
• Add ultrasound measurements
• Monitor redating recommendations
• Store clinical notes
• Track pregnancy progression over time
• iCloud sync across all your devices

Who Is OB Wheel For?

Healthcare professionals: Obstetricians, gynecologists, midwives, nurse practitioners, family medicine physicians, OB/GYN residents, medical students, and labor & delivery nurses.

Expectant parents: Track your pregnancy week by week, understand your ultrasound dates, know when you’ll reach each trimester, and share milestones with family.

Privacy First

All calculations are performed on-device. Patient data is stored securely in your private iCloud — no third-party tracking, no accounts required. You own your data.

OB Wheel is free to download.