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Calcimator

Pregnancy Wheel Calculator

Calculate gestational age, estimated due date, and trimester from the last menstrual period (LMP) using Naegele's rule.

Inputs

days

Results

Gestational Age (Weeks)

12weeks

Trimester

1

Plus Days0days
Days Until EDD196days
Weeks Until EDD28weeks
Days Remaining196days
Pregnancy Progress30%
How to Use This Calculator
  1. Enter the first day of the last menstrual period (LMP).
  2. Review estimated due date (EDD), gestational age in weeks and days, and trimester.
  3. Confirm with first-trimester ultrasound dating when available.

How the result changes with Days Since LMP

Days Since LMPGestational Age (Weeks)Trimester
304weeks1
10515weeks2
19527weeks2
27038weeks3

What each input means

Days Since LMP
Number of days since the first day of the last menstrual period. Typical pregnancy is 280 days (40 weeks).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    Days Since LMP = 84 = 1 input(s) provided
  2. Calculate Gestational Age
    Gestational Age
    12 = 12
  3. Calculate Trimester
    Trimester
    1 = 1
  4. Calculate Plus Days
    Plus Days
    0 = 0
  5. Calculate Days Until EDD
    Days Until EDD = max(0
    196 = 196

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