Gestational Age Calculator
Enter your LMP date or a known gestational age from an ultrasound to instantly calculate your current gestational age in weeks and days, plus your estimated due date.
Use the Gestational Age Calculator
Gestational Age Calculator
Enter the first day of your most recent period.
The date the ultrasound was performed.
Weeks (0–42)
Days (0–6)
Fill in the form and click Calculate
Your gestational age will appear here
Current Gestational Age
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Estimated Due Date
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Trimester
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Days to EDD
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remaining
Calculation method
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Pregnancy Milestones
Summary
This calculator determines current gestational age using two methods: (1) from the first day of the last menstrual period (LMP), applying the standard formula of elapsed days divided into weeks and days with EDD = LMP + 280 days; or (2) from a known gestational age recorded at an ultrasound, advanced by the number of days since that scan. All arithmetic runs in your browser — no data is transmitted.
How it works
- Method 1 computes elapsed days from LMP to today, converts to weeks plus remainder days, and adds 280 days for the EDD. Method 2 converts the ultrasound gestational age to a total day count, adds elapsed days since the scan, then converts back to weeks and days; the EDD is computed by subtracting the total gestational days from today and adding 280.
Use cases
- Find out exactly how many weeks and days pregnant you are today.
- Calculate your estimated due date from your LMP date.
- Update gestational age forward from an ultrasound measurement.
- Cross-check your provider's gestational age estimate.
- Track pregnancy progress between prenatal visits.