Free calculator

Due date by ultrasound

Estimate your due date from an ultrasound's gestational age measurement.

Estimate, not a diagnosis. This tool gives an educational estimate based on the numbers you enter. It cannot account for your individual health history — consult a healthcare professional for anything clinical.

Ultrasound date

July 2026

SMTWTFS

Gestational age at scan — weeks

12weeks

From your ultrasound report.

Gestational age at scan — extra days

0days

Notes

Ultrasound dating is typically more accurate than LMP-based dating in early pregnancy. Accuracy varies by gestational age and measurement type — early first-trimester crown-rump length (CRL) is the most precise.

Limitations

Later scans have wider margins of error. Your care provider's dating should take precedence over this estimate.