Pregnancy Trimester Calculator
Result
Current Trimester Third Trimester 37 weeks pregnant.
1st Trimester (weeks 1–12) 1 January 2026 – 1 April 2026
2nd Trimester (weeks 13–26) 2 April 2026 – 8 July 2026
3rd Trimester (weeks 27–40) 9 July 2026 – 8 October 2026
Pregnancy Trimester Calculator is a health and wellness calculator that helps you calculate a pregnancy or fetal development metric. The formula used is: Gestational age = today − LMP (in weeks)\nT1: weeks 1–12, T2: weeks 13–26, T3: weeks 27–40. Enter values using the units shown next to each input field (e.g. kg, cm, years).
Formula
Gestational age = today − LMP (in weeks)
T1: weeks 1–12, T2: weeks 13–26, T3: weeks 27–40
- Pregnancy Trimester Calculator gives you a fast estimate using your inputs and updates instantly when you change any value.
- Formula: Gestational age = today − LMP (in weeks)\nT1: weeks 1–12, T2: weeks 13–26, T3: weeks 27–40
- 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
Suppose you enter: your chosen values. The calculator applies the formula (Gestational age = today − LMP (in weeks)\nT1: weeks 1–12, T2: weeks 13–26, T3: weeks 27–40) and shows all output values below. Change any input field to immediately see how the result changes.
Frequently asked questions
What is the Pregnancy Trimester?
The Pregnancy Trimester Calculator is a health and wellness calculator that helps you calculate a pregnancy or fetal development metric. 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 a pregnancy or fetal development metric 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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