Pregnancy Wheel Calculator
An interactive visual pregnancy wheel — just like the one your doctor uses. Enter your LMP date to see your due date, current week, trimester, and key milestones displayed on a circular wheel.
How It Works
The pregnancy wheel is a digital recreation of the physical obstetric wheel (or "gestational calculator") that has been a staple tool in doctors' offices for decades. It provides a quick, visual way to understand where you are in your pregnancy.
Here is how to use it:
- Enter the first day of your last menstrual period (LMP) in the date field.
- Click "Generate Pregnancy Wheel" to create your personalized wheel.
- The wheel displays all 40 weeks of pregnancy in a circle. Each segment is one week, color-coded by trimester: amber (first), blue (second), and green (third).
- A red indicator marks your current position on the wheel so you can see at a glance exactly where you are.
- Key milestones (heartbeat detection, anatomy scan, viability, full term, and due date) are marked inside the ring for easy reference.
The due date calculation uses Naegele's rule, which adds 280 days (40 weeks) to your LMP date. This is the same method used by healthcare providers worldwide.
Frequently Asked Questions
What is a pregnancy wheel?
A pregnancy wheel (also called an obstetric wheel or gestational calculator) is a circular tool traditionally used by doctors and midwives to quickly determine due dates and gestational age. The outer ring shows calendar dates, and the inner ring shows the corresponding weeks of pregnancy. Our digital version replicates this tool and adds color-coding by trimester and milestone markers.
How do I read the pregnancy wheel?
The wheel displays 40 weeks arranged in a circle, starting from your LMP date. Each segment represents one week, color-coded by trimester: amber for the first trimester (weeks 0-12), blue for the second (weeks 13-26), and green for the third (weeks 27-40). The red indicator marks your current position. Key milestones are labeled inside the ring.
Is the digital pregnancy wheel as accurate as the physical one?
Yes, our digital pregnancy wheel uses the same calculation method (Naegele's rule) as the physical wheels used in medical offices. Both add 280 days to your LMP date. The digital version has the advantage of automatically calculating your current position and displaying it visually.
Why does my doctor use a pregnancy wheel instead of just counting weeks?
Pregnancy wheels allow healthcare providers to quickly look up dates for upcoming appointments, tests, and milestones without manual calculation. They can instantly see what week corresponds to a specific date, or find the date for a specific gestational age. They remain popular because of their speed and simplicity in clinical settings.
Can I use the pregnancy wheel if I don't know my LMP?
This wheel requires your LMP date as input. If you don't know your LMP but have a due date from your doctor (often determined by ultrasound), you can calculate your LMP by subtracting 280 days from your due date. Alternatively, try our due date calculator which accepts different input methods.
Medical Disclaimer
This calculator is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider for medical decisions regarding your pregnancy.