Reverse Due Date Calculator

Estimate conception date from due date.

Input Parameters

Due Date

Standard Gestation: This calculation assumes a standard 40-week (280 day) pregnancy from the start of the last period.

Estimated Milestones

Conception DateJuly 6, 2026Estimated Onset

LMP DateJune 22, 2026

Progress9w 5d

You are currently in your first trimester.

Pregnancy Timeline Analysis

Disclaimer: This tool is for informational purposes only and is not a substitute for professional medical advice.

About this calculator

Overview

Conception = Due date − 266 days.

Fun Facts

Formula: Conception = Due date − 266 days