How is a due date calculated?

Due dates are calculated using Naegele's Rule: add 280 days (40 weeks) to the first day of the last menstrual period (LMP). This assumes a 28-day cycle with ovulation on day 14. Ultrasound dating in the first trimester is the most accurate method for confirming gestational age.

What is the Bishop Score?

The Bishop Score assesses cervical readiness for labor induction using five factors: dilation, effacement, station, consistency, and position. A score ≥8 suggests a favorable cervix with a high likelihood of successful vaginal delivery. A low score may indicate the need for cervical ripening before induction.

What does the APGAR score measure?

The APGAR score is assessed at 1 and 5 minutes after birth, evaluating five criteria: Appearance (skin color), Pulse, Grimace (reflex irritability), Activity (muscle tone), and Respiration. Scores range from 0–10, with 7–10 considered reassuring.

Obstetric & Pregnancy Calculators

Pregnancy tools including due date calculator, Bishop Score, APGAR Score, gestational age calculator, contraction timer, and fetal weight estimator. Essential tools for prenatal care and labor assessment.

This category currently includes 10 tools, including Due Date Calculator, Period Calculator, and Ovulation Calculator.

These resources are built for clinicians, trainees, and medically informed patients who need fast bedside calculations. Use the results as decision support and pair them with full clinical context and local guidelines.

All Obstetrics Tools (10)

Due Date Calculator

Calculate your estimated due date (EDD) from your last menstrual period using Naegele's rule. Track gestational age and trimester.

Period Calculator

Predict your next period date using your last menstrual period and average cycle length. See cycle day, fertile window, and upcoming period dates.

Ovulation Calculator

Estimate your ovulation date and fertile window using cycle length and last period date. See best days to conceive and estimated due date if conception occurs.

Conception Calculator

Estimate your conception date from your last menstrual period and cycle length, or from your estimated due date. Includes likely conception window and ovulation estimate.

Bishop Score

Calculate the Bishop Score to assess cervical favorability for labor induction. Predicts likelihood of successful vaginal delivery.

Apgar Score

Calculate the Apgar Score to quickly assess newborn health at 1 and 5 minutes after birth. Evaluates appearance, pulse, grimace, activity, and respiration.

Gestational Age Calculator

Calculate gestational age in weeks and days from last menstrual period (LMP). Get trimester, estimated due date (EDD), and days remaining.

Fetal Weight Calculator

Enter BPD, HC, AC, and FL ultrasound values to get estimated fetal weight (EFW) using the Hadlock formula. Includes percentile and SGA/AGA/LGA classification. Free, instant.

Contraction Timer

Time contractions during labor to track duration, frequency, and pattern for the 5-1-1 rule.

Apgar Timer

Live timer for Apgar scoring at 1 and 5 minutes after birth with real-time assessment.

Frequently Asked Questions

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