Animal Gestation Calculator

White-tailed Deer Gestation Calculator

Last updated

A white-tailed deer's gestation period is about 200 days, or roughly 6 months and 2 weeks, though it ranges from 187 to 222 days depending on breed and individual animal.

Calculate a fawn due date

What do you know?

Estimated fawning date

Monday, 19 April 2027

Earliest

6 Apr 2027

Latest

11 May 2027

200 days remaining0% complete

0 of 200 days elapsed

Milestone timeline

Key White-tailed deer pregnancy milestones with calculated calendar dates
DayMilestoneDate
0Doe bred during the rut; most adult does conceive on their first heat1 Oct 2026
28A doe that was not bred cycles back into heat about 28 days later29 Oct 2026
40Pregnancy can be confirmed by blood test (PSPB) or ultrasound on farmed deer10 Nov 2026
150Fetal growth accelerates; raise feed quality on farms and avoid handling28 Feb 2027
185Udder begins to fill; set up quiet, well-covered fawning areas4 Apr 2027
200Expected fawning date19 Apr 2027

What to do next

How to use the white-tailed deer gestation calculator

  1. 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. 2. Refine the inputs. The calculator uses the 200-day average for this species.
  3. 3. Plan around the range. Use the earliest and latest dates and the milestone timeline to schedule checks, feed changes and preparation of the fawning area.

How long is a white-tailed deer's gestation period?

The average is 200 days from breeding to fawning, about 6 months and 2 weeks. Anything between 187 and 222 days is normal, and a typical litter is 1-2 fawns. Treat the calculated date as the middle of that window rather than a fixed appointment.

White-tailed deer gestation table: breeding date to fawning date

Breeding dates one week apart with the matching fawning date at 200 days.

Twelve sample White-tailed deer breeding dates and their calculated due dates
Breeding dateExpected fawning date
1 Oct 202619 Apr 2027
8 Oct 202626 Apr 2027
15 Oct 20263 May 2027
22 Oct 202610 May 2027
29 Oct 202617 May 2027
5 Nov 202624 May 2027
12 Nov 202631 May 2027
19 Nov 20267 Jun 2027
26 Nov 202614 Jun 2027
3 Dec 202621 Jun 2027
10 Dec 202628 Jun 2027
17 Dec 20265 Jul 2027

Working backwards from a target fawning date

If you want fawns on the ground in a particular week, switch the calculator to target date mode and enter the date you are aiming for. It subtracts 200 days to give the breeding date to book, plus the earliest and latest service dates that still land inside your window.

White-tailed deer gestation calculator FAQs

How long is a white-tailed deer pregnant?

About 200 days, roughly six and a half months. Normal gestation runs from around 187 to 222 days, so most does fawn within a week or two either side of the 200-day mark.

When are whitetail fawns born?

In most of the northern and midwestern United States, mainly from late May through June, about 200 days after the November rut peak. In southern states with a later rut, fawning can run into July, August or later.

How common are twins in white-tailed deer?

Twins are the norm for healthy adult does in good habitat. First-time mothers and does in poor condition more often have a single fawn, and triplets are possible but uncommon.

When is the whitetail rut?

Across most of the northern range breeding peaks in November. Day length triggers it, so the rut is tight and predictable in the north and more spread out and variable in the south, where it can fall well into winter.

If a doe is bred in December, when will she fawn?

Around 200 days later, so a doe bred in mid December would usually fawn in early July. Enter the breeding date in the calculator above for the exact estimated date.

More gestation pages

Wild animal gestation chart