Pregnancy Due Date Calculator
Calculate pregnancy due date, estimated conception, and gestational progress using Naegele rule.
Enter Your Dimensions
US • ftHow We Calculated This
• Only about 4–5% of babies arrive on their exact calculated due date; between 37 and 42 weeks is considered full term.
Formula & Volumetric Method
Naegele's rule: Estimated Due Date = First Day of Last Menstrual Period (LMP) + 280 days (40 gestational weeks).
Calculations are performed strictly using standard civil engineering constants. Volumetric outputs are normalized to true compaction rates, ensuring purchased quantities match jobsite yields.
Jobsite Engineering Guidelines
- Gestational age starts on day 1 of the last menstrual period, roughly 2 weeks prior to conception.
- Trimester 1: Week 1 to end of Week 13.
- Trimester 2: Week 14 to end of Week 27.
- Trimester 3: Week 28 through delivery (Week 40+).
Frequently Asked Questions
How accurate is the Pregnancy Due Date Calculator for ordering materials?
Our calculations match standard store packaging sizes in the US, Canada, UK, and Australia. We include a safety waste buffer (default 8% to 12%) so you do not run short due to uneven ground or spillage.
Why should I add extra for waste when ordering?
Uneven ground, cutting scrap, and leftover mix in the wheelbarrow or mixer drum consume an extra 5% to 15% of material. Ordering only the exact measurement usually leaves you short, which can lead to expensive extra delivery fees.
Does this calculator support both Imperial and Metric units?
Yes. You can switch between US Customary (feet, inches, cubic yards, pounds), Canadian units, UK metric, and Australian standards using the region selector in the header or the unit dropdown on each input.