Pregnancy Week Calculator

date matching the choice above; also MM/DD/YYYY
days
typically 28; counted from period to period
empty = today

Result

Weeks pregnant
20 weeks 4 days
Current week
Week 21 of pregnancy
Trimester
Second trimester (14w 0d to 27w 6d)
Month of pregnancy
Month 6 (counted in 4-week months)
Estimated due date
Wednesday, 10 February 2027
Until the due date
136 days to go
Progress (of 40 weeks)
51.43%
Calculation
  • Start (0w 0d) = first day of last period: 06/05/2026; due date = + 280 days: 10/02/2027
  • Reference date: 27/09/2026
  • Since 0w 0d: 144 days = 20 full weeks + 4 days = 20 weeks 4 days
  • Month: 144 days ÷ 28, rounded down + 1 = 6
This is only an estimate and does not replace medical advice. The gestational age in your pregnancy notes is the one that counts.