Horse Gestation Chart

A mare carries her foal about 340 days. Find the day she was covered, and the date beside it is her foaling date. Change the days if you like, then print the whole year.

You typeWe calculate

How it's calculated

Due = date bred + 340 days
Range = 335 to 342 days

Dates are counted in whole days, so leap years come out right. February 29 is in the chart only in a leap year.

Sources and worked example

Horse gestation chart · 340 days

Foaling dates for mares bred January to December 2026

Find the day she was covered in its month. The date beside it is her due date. Typical range: 335 to 342 days after breeding.

12 months · prints on 2 pages

January 2026Due Dec 7, 2026 to Jan 6, 2027
Covered	Due
1	Dec 7
2	Dec 8
3	Dec 9
4	Dec 10
5	Dec 11
6	Dec 12
7	Dec 13
8	Dec 14
9	Dec 15
10	Dec 16
11	Dec 17
12	Dec 18
13	Dec 19
14	Dec 20
15	Dec 21
16	Dec 22
17	Dec 23
18	Dec 24
19	Dec 25
20	Dec 26
21	Dec 27
22	Dec 28
23	Dec 29
24	Dec 30
25	Dec 31
26	Jan 1
27	Jan 2
28	Jan 3
29	Jan 4
30	Jan 5
31	Jan 6

February 2026Due Jan 7 to Feb 3, 2027
Covered	Due
1	Jan 7
2	Jan 8
3	Jan 9
4	Jan 10
5	Jan 11
6	Jan 12
7	Jan 13
8	Jan 14
9	Jan 15
10	Jan 16
11	Jan 17
12	Jan 18
13	Jan 19
14	Jan 20
15	Jan 21
16	Jan 22
17	Jan 23
18	Jan 24
19	Jan 25
20	Jan 26
21	Jan 27
22	Jan 28
23	Jan 29
24	Jan 30
25	Jan 31
26	Feb 1
27	Feb 2
28	Feb 3

March 2026Due Feb 4 to Mar 6, 2027
Covered	Due
1	Feb 4
2	Feb 5
3	Feb 6
4	Feb 7
5	Feb 8
6	Feb 9
7	Feb 10
8	Feb 11
9	Feb 12
10	Feb 13
11	Feb 14
12	Feb 15
13	Feb 16
14	Feb 17
15	Feb 18
16	Feb 19
17	Feb 20
18	Feb 21
19	Feb 22
20	Feb 23
21	Feb 24
22	Feb 25
23	Feb 26
24	Feb 27
25	Feb 28
26	Mar 1
27	Mar 2
28	Mar 3
29	Mar 4
30	Mar 5
31	Mar 6

April 2026Due Mar 7 to Apr 5, 2027
Covered	Due
1	Mar 7
2	Mar 8
3	Mar 9
4	Mar 10
5	Mar 11
6	Mar 12
7	Mar 13
8	Mar 14
9	Mar 15
10	Mar 16
11	Mar 17
12	Mar 18
13	Mar 19
14	Mar 20
15	Mar 21
16	Mar 22
17	Mar 23
18	Mar 24
19	Mar 25
20	Mar 26
21	Mar 27
22	Mar 28
23	Mar 29
24	Mar 30
25	Mar 31
26	Apr 1
27	Apr 2
28	Apr 3
29	Apr 4
30	Apr 5

May 2026Due Apr 6 to May 6, 2027
Covered	Due
1	Apr 6
2	Apr 7
3	Apr 8
4	Apr 9
5	Apr 10
6	Apr 11
7	Apr 12
8	Apr 13
9	Apr 14
10	Apr 15
11	Apr 16
12	Apr 17
13	Apr 18
14	Apr 19
15	Apr 20
16	Apr 21
17	Apr 22
18	Apr 23
19	Apr 24
20	Apr 25
21	Apr 26
22	Apr 27
23	Apr 28
24	Apr 29
25	Apr 30
26	May 1
27	May 2
28	May 3
29	May 4
30	May 5
31	May 6

June 2026Due May 7 to Jun 5, 2027
Covered	Due
1	May 7
2	May 8
3	May 9
4	May 10
5	May 11
6	May 12
7	May 13
8	May 14
9	May 15
10	May 16
11	May 17
12	May 18
13	May 19
14	May 20
15	May 21
16	May 22
17	May 23
18	May 24
19	May 25
20	May 26
21	May 27
22	May 28
23	May 29
24	May 30
25	May 31
26	Jun 1
27	Jun 2
28	Jun 3
29	Jun 4
30	Jun 5

Horse gestation chart (340 days), continued

July 2026Due Jun 6 to Jul 6, 2027
Covered	Due
1	Jun 6
2	Jun 7
3	Jun 8
4	Jun 9
5	Jun 10
6	Jun 11
7	Jun 12
8	Jun 13
9	Jun 14
10	Jun 15
11	Jun 16
12	Jun 17
13	Jun 18
14	Jun 19
15	Jun 20
16	Jun 21
17	Jun 22
18	Jun 23
19	Jun 24
20	Jun 25
21	Jun 26
22	Jun 27
23	Jun 28
24	Jun 29
25	Jun 30
26	Jul 1
27	Jul 2
28	Jul 3
29	Jul 4
30	Jul 5
31	Jul 6

August 2026Due Jul 7 to Aug 6, 2027
Covered	Due
1	Jul 7
2	Jul 8
3	Jul 9
4	Jul 10
5	Jul 11
6	Jul 12
7	Jul 13
8	Jul 14
9	Jul 15
10	Jul 16
11	Jul 17
12	Jul 18
13	Jul 19
14	Jul 20
15	Jul 21
16	Jul 22
17	Jul 23
18	Jul 24
19	Jul 25
20	Jul 26
21	Jul 27
22	Jul 28
23	Jul 29
24	Jul 30
25	Jul 31
26	Aug 1
27	Aug 2
28	Aug 3
29	Aug 4
30	Aug 5
31	Aug 6

September 2026Due Aug 7 to Sep 5, 2027
Covered	Due
1	Aug 7
2	Aug 8
3	Aug 9
4	Aug 10
5	Aug 11
6	Aug 12
7	Aug 13
8	Aug 14
9	Aug 15
10	Aug 16
11	Aug 17
12	Aug 18
13	Aug 19
14	Aug 20
15	Aug 21
16	Aug 22
17	Aug 23
18	Aug 24
19	Aug 25
20	Aug 26
21	Aug 27
22	Aug 28
23	Aug 29
24	Aug 30
25	Aug 31
26	Sep 1
27	Sep 2
28	Sep 3
29	Sep 4
30	Sep 5

October 2026Due Sep 6 to Oct 6, 2027
Covered	Due
1	Sep 6
2	Sep 7
3	Sep 8
4	Sep 9
5	Sep 10
6	Sep 11
7	Sep 12
8	Sep 13
9	Sep 14
10	Sep 15
11	Sep 16
12	Sep 17
13	Sep 18
14	Sep 19
15	Sep 20
16	Sep 21
17	Sep 22
18	Sep 23
19	Sep 24
20	Sep 25
21	Sep 26
22	Sep 27
23	Sep 28
24	Sep 29
25	Sep 30
26	Oct 1
27	Oct 2
28	Oct 3
29	Oct 4
30	Oct 5
31	Oct 6

November 2026Due Oct 7 to Nov 5, 2027
Covered	Due
1	Oct 7
2	Oct 8
3	Oct 9
4	Oct 10
5	Oct 11
6	Oct 12
7	Oct 13
8	Oct 14
9	Oct 15
10	Oct 16
11	Oct 17
12	Oct 18
13	Oct 19
14	Oct 20
15	Oct 21
16	Oct 22
17	Oct 23
18	Oct 24
19	Oct 25
20	Oct 26
21	Oct 27
22	Oct 28
23	Oct 29
24	Oct 30
25	Oct 31
26	Nov 1
27	Nov 2
28	Nov 3
29	Nov 4
30	Nov 5

December 2026Due Nov 6 to Dec 6, 2027
Covered	Due
1	Nov 6
2	Nov 7
3	Nov 8
4	Nov 9
5	Nov 10
6	Nov 11
7	Nov 12
8	Nov 13
9	Nov 14
10	Nov 15
11	Nov 16
12	Nov 17
13	Nov 18
14	Nov 19
15	Nov 20
16	Nov 21
17	Nov 22
18	Nov 23
19	Nov 24
20	Nov 25
21	Nov 26
22	Nov 27
23	Nov 28
24	Nov 29
25	Nov 30
26	Dec 1
27	Dec 2
28	Dec 3
29	Dec 4
30	Dec 5
31	Dec 6

Due date = date bred + 340 days. Typical range 335 to 342 days.

Tracking more than one of your mares this season?

An estimate for planning, not veterinary advice. Work with your vet on pregnancy exams, vaccines and foaling.

The full template

Skip the lookup: one file works out each mare's foaling date

Breeding & Birthing: enter each cover date and species, and the due date and days-to-due countdown fill in
An editable gestation table on Settings, with horses at 340 days
Health Log sets the next due date for every vaccine and dewormer, flagged Due Soon or Overdue
Feed, hay and vet costs by species, with sales and profit for the year

Livestock Tracker Spreadsheet$17.99One-time · instant downloadExcel + Google Sheets + PDF guide5.0 shop rating on Etsy

How to use the horse gestation chart

Each block is one month of covers. Find the day the mare was covered or inseminated in the left column. The date in the right column is when she should foal, 340 days later. A line marks where the foaling dates move into a new month.

For one mare, with her first and last cover, ultrasound checks, EHV-1 vaccines and the move to the foaling site, use the horse gestation calculator.

Why 340 days, and why the window is wide

Purdue's College of Veterinary Medicine puts the average at 340 days and the normal range at 315 to 365 days. The University of Minnesota says most mares foal between day 335 and day 342, which is the typical range shown above the chart. Treat the date as the middle of a window, not a deadline.

If your mare's past foals came early or late, type her own number into the gestation days box and the chart redraws.

Printing the chart

"Print this" prints only the chart: the first six months on page one and the last six on page two. It fits Letter or A4 paper. Set "Start with" to the first month of your breeding season so the whole season fits on one printout.

Leap years are handled. February 29 shows up only in a leap year, such as 2028, and every date is counted in whole days. A mare covered on April 1, 2026 is due Sun, Mar 7, 2027. One covered on April 1, 2027 is due Mon, Mar 6, 2028, a day earlier on the calendar, because February 29, 2028 falls inside her pregnancy.

Sources

FAQ

Common questions

How long is a horse pregnant?

About 340 days, or 11 months. Purdue gives 315 to 365 days as the normal range, and the University of Minnesota says most mares foal between day 335 and day 342.

How do I read a horse gestation chart?

Find the month the mare was covered, then the day in the left column. The date beside it is her foaling date. A mare covered on May 1, 2026 is due Tue, Apr 6, 2027.

She was covered more than once. Which date do I use?

Use the last cover or AI date, which is usually closest to when she ovulated. If your vet confirmed the ovulation date, look that up instead.

Is it normal for a mare to go past 340 days?

Yes. Gestation in mares varies more than in most livestock, and Purdue counts anything from 315 to 365 days as normal. Ask your vet about a foal born well before 320 days, or a mare still waiting past 365.

Why is the foaling date earlier in the year than the cover date?

Because 340 days is 25 days short of a year. A mare foals about three and a half weeks earlier on the calendar than the day she was covered, in the following year.

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