Due Date by Ultrasound (CRL)

mm
From a first-trimester ultrasound (valid for CRL 2–84 mm).
Health Updated 14 Jun 2026

Due Date by Ultrasound (CRL) is a health and wellness calculator that helps you calculate date differences, days between dates, or future/past dates. The formula used is: GA (days) = 8.052 × √CRL + 23.73 (Robinson-Fleming, CRL in mm)\nEDD = scan date + (280 − GA days). Enter values using the units shown next to each input field (e.g. kg, cm, years).

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.
  • For information only. Clinical dating should be confirmed by your sonographer.

Formula

GA (days) = 8.052 × √CRL + 23.73 (Robinson-Fleming, CRL in mm) EDD = scan date + (280 − GA days)
  • Due Date by Ultrasound (CRL) gives you a fast estimate using your inputs and updates instantly when you change any value.
  • Formula: GA (days) = 8.052 × √CRL + 23.73 (Robinson-Fleming, CRL in mm)\nEDD = scan date + (280 − GA days)
  • Input definitions: • Crown-Rump Length (CRL): the numeric crown-rump length (crl) used in the calculation
  • Enter values using the units shown next to each input field (e.g. kg, cm, years).
  • This calculator uses widely accepted health formulas and returns screening estimates only. It does not replace a diagnosis from a qualified healthcare professional.
  • Compare your result with published reference ranges. Values outside the normal range warrant a conversation with your doctor.
  • Practical tip: test a low, medium, and high scenario to understand sensitivity before making decisions.

Example Calculation

Inputs
  • Crown-Rump Length (CRL): 30 mm

Suppose you enter: Crown-Rump Length (CRL) = 30. The calculator applies the formula (GA (days) = 8.052 × √CRL + 23.73 (Robinson-Fleming, CRL in mm)\nEDD = scan date + (280 − GA days)) and shows all output values below. Change any input field to immediately see how the result changes.

Frequently asked questions

What is the Due Date by Ultrasound (CRL)?
The Due Date by Ultrasound (CRL) is a health and wellness calculator that helps you calculate date differences, days between dates, or future/past dates. Enter values using the units shown next to each input field (e.g. kg, cm, years).
When should I use this calculator?
Use this calculator whenever you need a quick, accurate result for date differences, days between dates, or future/past dates without working through the arithmetic manually.
What units should I enter?
Enter values using the units shown next to each input field (e.g. kg, cm, years).
How accurate are the results?
This calculator uses widely accepted health formulas and returns screening estimates only. It does not replace a diagnosis from a qualified healthcare professional.
How do I interpret the result?
Compare your result with published reference ranges. Values outside the normal range warrant a conversation with your doctor.
How can I verify the calculation manually?
Use the displayed formula and work through the numbers step by step. If your manual result differs slightly, check rounding and unit conversions first.
Can I use this for planning and budgeting?
Yes. Run best-case, expected, and worst-case inputs to compare outcomes and make safer planning decisions.

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