Manatee Gestation Calculator
Last updated
A manatee's gestation period is about 380 days, or roughly 12 months and 2 weeks, though it ranges from 365 to 400 days depending on breed and individual animal.
Calculate a calf due date
Estimated calving date
Wednesday, 20 October 2027
Earliest
5 Oct 2027
Latest
9 Nov 2027
0 of 380 days elapsed
Milestone timeline
| Day | Milestone | Date |
|---|---|---|
| 0 | Mating within a mating herd of several males following one female | 5 Oct 2026 |
| 180 | Mid gestation; the calf grows steadily | 3 Apr 2027 |
| 330 | Late gestation; the female seeks calm, sheltered water | 31 Aug 2027 |
| 380 | Expected calving, roughly 12 to 14 months after mating | 20 Oct 2027 |
How to use the manatee gestation calculator
- 1. Choose what you know. Enter the breeding date to get a due date, or switch to the target due date mode to work backwards to the breeding date you need.
- 2. Refine the inputs. The calculator uses the 380-day average for this species.
- 3. Plan around the range. Use the earliest and latest dates and the milestone timeline to schedule checks, feed changes and preparation of the calving area.
How long is a manatee's gestation period?
The average is 380 days from breeding to calving, about 12 months and 2 weeks. Anything between 365 and 400 days is normal, and a typical litter is 1 calf. Treat the calculated date as the middle of that window rather than a fixed appointment.
Manatee gestation table: breeding date to calving date
Breeding dates one week apart with the matching calving date at 380 days.
| Breeding date | Expected calving date |
|---|---|
| 5 Oct 2026 | 20 Oct 2027 |
| 12 Oct 2026 | 27 Oct 2027 |
| 19 Oct 2026 | 3 Nov 2027 |
| 26 Oct 2026 | 10 Nov 2027 |
| 2 Nov 2026 | 17 Nov 2027 |
| 9 Nov 2026 | 24 Nov 2027 |
| 16 Nov 2026 | 1 Dec 2027 |
| 23 Nov 2026 | 8 Dec 2027 |
| 30 Nov 2026 | 15 Dec 2027 |
| 7 Dec 2026 | 22 Dec 2027 |
| 14 Dec 2026 | 29 Dec 2027 |
| 21 Dec 2026 | 5 Jan 2028 |
Working backwards from a target calving date
If you want calfs on the ground in a particular week, switch the calculator to target date mode and enter the date you are aiming for. It subtracts 380 days to give the breeding date to book, plus the earliest and latest service dates that still land inside your window.