Home › Sheep Gestation & Lambing Calculator Sheep Gestation & Lambing Calculator Ewes carry their lambs for about 147 days (normally 144 to 152). Enter the tupping or mating date, the dates the ram went in and came out, or the date you want lambing to start.
Sheep due date calculator One breeding date Ram in → ram out Work back from lambing
Gestation length Standard (147 days) Custom length… Breeding date
Pick a date to see the due date.
How the calculator works It adds the gestation length to the date you enter, counting calendar days (including leap days). The default for sheep is 147 days, and the result also shows a window of 144 to 152 days (normal range). Change the length if your vet, breed society or sire information says otherwise. All calculations run in your browser; nothing you enter is sent anywhere.
Worked examples A ewe tupped on October 1, 2026, is due around February 25, 2027 , with lambs normally arriving between February 22 and March 2. Rams in on October 1 and out on November 4 (two 17-day cycles) gives lambing from about February 25 to March 31, 2027. Sheep gestation facts Gestation 147 days (144 to 152) Heat cycle 17 days (14 to 19) Heat lasts 30 to 35 hours (20 to 42)
Common questions How long is a ewe's heat cycle? About 17 days, varying from 14 to 19 (New Mexico State University). Two cycles with the ram, about 34 days, gives most ewes two chances to settle. Raddle colours changed every cycle show which ewes repeated.
Can lambs come early? Yes. New Mexico State University notes high temperatures and high nutrition can shorten gestation by two or three days, and the normal range is 144 to 152 days.
Joining, tupping or mating? They all mean the same thing here: the day the ram mated the ewe, or the day he went in with the flock. Use whichever date you recorded.
Printable sheep gestation chart Show the full lambing table for every breeding date of the year Breeding year 2025 2026 2027 2028 Print this table
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Sheep, 147-day gestation. Find the date the ewe was bred in the left column; the expected lambing date is on the right.
Bred in January 2026 Bred Due Jan 1 May 28 Jan 2 May 29 Jan 3 May 30 Jan 4 May 31 Jan 5 Jun 1 Jan 6 Jun 2 Jan 7 Jun 3 Jan 8 Jun 4 Jan 9 Jun 5 Jan 10 Jun 6 Jan 11 Jun 7 Jan 12 Jun 8 Jan 13 Jun 9 Jan 14 Jun 10 Jan 15 Jun 11 Jan 16 Jun 12 Jan 17 Jun 13 Jan 18 Jun 14 Jan 19 Jun 15 Jan 20 Jun 16 Jan 21 Jun 17 Jan 22 Jun 18 Jan 23 Jun 19 Jan 24 Jun 20 Jan 25 Jun 21 Jan 26 Jun 22 Jan 27 Jun 23 Jan 28 Jun 24 Jan 29 Jun 25 Jan 30 Jun 26 Jan 31 Jun 27
Bred in February 2026 Bred Due Feb 1 Jun 28 Feb 2 Jun 29 Feb 3 Jun 30 Feb 4 Jul 1 Feb 5 Jul 2 Feb 6 Jul 3 Feb 7 Jul 4 Feb 8 Jul 5 Feb 9 Jul 6 Feb 10 Jul 7 Feb 11 Jul 8 Feb 12 Jul 9 Feb 13 Jul 10 Feb 14 Jul 11 Feb 15 Jul 12 Feb 16 Jul 13 Feb 17 Jul 14 Feb 18 Jul 15 Feb 19 Jul 16 Feb 20 Jul 17 Feb 21 Jul 18 Feb 22 Jul 19 Feb 23 Jul 20 Feb 24 Jul 21 Feb 25 Jul 22 Feb 26 Jul 23 Feb 27 Jul 24 Feb 28 Jul 25
Bred in March 2026 Bred Due Mar 1 Jul 26 Mar 2 Jul 27 Mar 3 Jul 28 Mar 4 Jul 29 Mar 5 Jul 30 Mar 6 Jul 31 Mar 7 Aug 1 Mar 8 Aug 2 Mar 9 Aug 3 Mar 10 Aug 4 Mar 11 Aug 5 Mar 12 Aug 6 Mar 13 Aug 7 Mar 14 Aug 8 Mar 15 Aug 9 Mar 16 Aug 10 Mar 17 Aug 11 Mar 18 Aug 12 Mar 19 Aug 13 Mar 20 Aug 14 Mar 21 Aug 15 Mar 22 Aug 16 Mar 23 Aug 17 Mar 24 Aug 18 Mar 25 Aug 19 Mar 26 Aug 20 Mar 27 Aug 21 Mar 28 Aug 22 Mar 29 Aug 23 Mar 30 Aug 24 Mar 31 Aug 25
Bred in April 2026 Bred Due Apr 1 Aug 26 Apr 2 Aug 27 Apr 3 Aug 28 Apr 4 Aug 29 Apr 5 Aug 30 Apr 6 Aug 31 Apr 7 Sep 1 Apr 8 Sep 2 Apr 9 Sep 3 Apr 10 Sep 4 Apr 11 Sep 5 Apr 12 Sep 6 Apr 13 Sep 7 Apr 14 Sep 8 Apr 15 Sep 9 Apr 16 Sep 10 Apr 17 Sep 11 Apr 18 Sep 12 Apr 19 Sep 13 Apr 20 Sep 14 Apr 21 Sep 15 Apr 22 Sep 16 Apr 23 Sep 17 Apr 24 Sep 18 Apr 25 Sep 19 Apr 26 Sep 20 Apr 27 Sep 21 Apr 28 Sep 22 Apr 29 Sep 23 Apr 30 Sep 24
Bred in May 2026 Bred Due May 1 Sep 25 May 2 Sep 26 May 3 Sep 27 May 4 Sep 28 May 5 Sep 29 May 6 Sep 30 May 7 Oct 1 May 8 Oct 2 May 9 Oct 3 May 10 Oct 4 May 11 Oct 5 May 12 Oct 6 May 13 Oct 7 May 14 Oct 8 May 15 Oct 9 May 16 Oct 10 May 17 Oct 11 May 18 Oct 12 May 19 Oct 13 May 20 Oct 14 May 21 Oct 15 May 22 Oct 16 May 23 Oct 17 May 24 Oct 18 May 25 Oct 19 May 26 Oct 20 May 27 Oct 21 May 28 Oct 22 May 29 Oct 23 May 30 Oct 24 May 31 Oct 25
Bred in June 2026 Bred Due Jun 1 Oct 26 Jun 2 Oct 27 Jun 3 Oct 28 Jun 4 Oct 29 Jun 5 Oct 30 Jun 6 Oct 31 Jun 7 Nov 1 Jun 8 Nov 2 Jun 9 Nov 3 Jun 10 Nov 4 Jun 11 Nov 5 Jun 12 Nov 6 Jun 13 Nov 7 Jun 14 Nov 8 Jun 15 Nov 9 Jun 16 Nov 10 Jun 17 Nov 11 Jun 18 Nov 12 Jun 19 Nov 13 Jun 20 Nov 14 Jun 21 Nov 15 Jun 22 Nov 16 Jun 23 Nov 17 Jun 24 Nov 18 Jun 25 Nov 19 Jun 26 Nov 20 Jun 27 Nov 21 Jun 28 Nov 22 Jun 29 Nov 23 Jun 30 Nov 24
Bred in July 2026 Bred Due Jul 1 Nov 25 Jul 2 Nov 26 Jul 3 Nov 27 Jul 4 Nov 28 Jul 5 Nov 29 Jul 6 Nov 30 Jul 7 Dec 1 Jul 8 Dec 2 Jul 9 Dec 3 Jul 10 Dec 4 Jul 11 Dec 5 Jul 12 Dec 6 Jul 13 Dec 7 Jul 14 Dec 8 Jul 15 Dec 9 Jul 16 Dec 10 Jul 17 Dec 11 Jul 18 Dec 12 Jul 19 Dec 13 Jul 20 Dec 14 Jul 21 Dec 15 Jul 22 Dec 16 Jul 23 Dec 17 Jul 24 Dec 18 Jul 25 Dec 19 Jul 26 Dec 20 Jul 27 Dec 21 Jul 28 Dec 22 Jul 29 Dec 23 Jul 30 Dec 24 Jul 31 Dec 25
Bred in August 2026 Bred Due Aug 1 Dec 26 Aug 2 Dec 27 Aug 3 Dec 28 Aug 4 Dec 29 Aug 5 Dec 30 Aug 6 Dec 31 Aug 7 Jan 1, 2027 Aug 8 Jan 2, 2027 Aug 9 Jan 3, 2027 Aug 10 Jan 4, 2027 Aug 11 Jan 5, 2027 Aug 12 Jan 6, 2027 Aug 13 Jan 7, 2027 Aug 14 Jan 8, 2027 Aug 15 Jan 9, 2027 Aug 16 Jan 10, 2027 Aug 17 Jan 11, 2027 Aug 18 Jan 12, 2027 Aug 19 Jan 13, 2027 Aug 20 Jan 14, 2027 Aug 21 Jan 15, 2027 Aug 22 Jan 16, 2027 Aug 23 Jan 17, 2027 Aug 24 Jan 18, 2027 Aug 25 Jan 19, 2027 Aug 26 Jan 20, 2027 Aug 27 Jan 21, 2027 Aug 28 Jan 22, 2027 Aug 29 Jan 23, 2027 Aug 30 Jan 24, 2027 Aug 31 Jan 25, 2027
Bred in September 2026 Bred Due Sep 1 Jan 26, 2027 Sep 2 Jan 27, 2027 Sep 3 Jan 28, 2027 Sep 4 Jan 29, 2027 Sep 5 Jan 30, 2027 Sep 6 Jan 31, 2027 Sep 7 Feb 1, 2027 Sep 8 Feb 2, 2027 Sep 9 Feb 3, 2027 Sep 10 Feb 4, 2027 Sep 11 Feb 5, 2027 Sep 12 Feb 6, 2027 Sep 13 Feb 7, 2027 Sep 14 Feb 8, 2027 Sep 15 Feb 9, 2027 Sep 16 Feb 10, 2027 Sep 17 Feb 11, 2027 Sep 18 Feb 12, 2027 Sep 19 Feb 13, 2027 Sep 20 Feb 14, 2027 Sep 21 Feb 15, 2027 Sep 22 Feb 16, 2027 Sep 23 Feb 17, 2027 Sep 24 Feb 18, 2027 Sep 25 Feb 19, 2027 Sep 26 Feb 20, 2027 Sep 27 Feb 21, 2027 Sep 28 Feb 22, 2027 Sep 29 Feb 23, 2027 Sep 30 Feb 24, 2027
Bred in October 2026 Bred Due Oct 1 Feb 25, 2027 Oct 2 Feb 26, 2027 Oct 3 Feb 27, 2027 Oct 4 Feb 28, 2027 Oct 5 Mar 1, 2027 Oct 6 Mar 2, 2027 Oct 7 Mar 3, 2027 Oct 8 Mar 4, 2027 Oct 9 Mar 5, 2027 Oct 10 Mar 6, 2027 Oct 11 Mar 7, 2027 Oct 12 Mar 8, 2027 Oct 13 Mar 9, 2027 Oct 14 Mar 10, 2027 Oct 15 Mar 11, 2027 Oct 16 Mar 12, 2027 Oct 17 Mar 13, 2027 Oct 18 Mar 14, 2027 Oct 19 Mar 15, 2027 Oct 20 Mar 16, 2027 Oct 21 Mar 17, 2027 Oct 22 Mar 18, 2027 Oct 23 Mar 19, 2027 Oct 24 Mar 20, 2027 Oct 25 Mar 21, 2027 Oct 26 Mar 22, 2027 Oct 27 Mar 23, 2027 Oct 28 Mar 24, 2027 Oct 29 Mar 25, 2027 Oct 30 Mar 26, 2027 Oct 31 Mar 27, 2027
Bred in November 2026 Bred Due Nov 1 Mar 28, 2027 Nov 2 Mar 29, 2027 Nov 3 Mar 30, 2027 Nov 4 Mar 31, 2027 Nov 5 Apr 1, 2027 Nov 6 Apr 2, 2027 Nov 7 Apr 3, 2027 Nov 8 Apr 4, 2027 Nov 9 Apr 5, 2027 Nov 10 Apr 6, 2027 Nov 11 Apr 7, 2027 Nov 12 Apr 8, 2027 Nov 13 Apr 9, 2027 Nov 14 Apr 10, 2027 Nov 15 Apr 11, 2027 Nov 16 Apr 12, 2027 Nov 17 Apr 13, 2027 Nov 18 Apr 14, 2027 Nov 19 Apr 15, 2027 Nov 20 Apr 16, 2027 Nov 21 Apr 17, 2027 Nov 22 Apr 18, 2027 Nov 23 Apr 19, 2027 Nov 24 Apr 20, 2027 Nov 25 Apr 21, 2027 Nov 26 Apr 22, 2027 Nov 27 Apr 23, 2027 Nov 28 Apr 24, 2027 Nov 29 Apr 25, 2027 Nov 30 Apr 26, 2027
Bred in December 2026 Bred Due Dec 1 Apr 27, 2027 Dec 2 Apr 28, 2027 Dec 3 Apr 29, 2027 Dec 4 Apr 30, 2027 Dec 5 May 1, 2027 Dec 6 May 2, 2027 Dec 7 May 3, 2027 Dec 8 May 4, 2027 Dec 9 May 5, 2027 Dec 10 May 6, 2027 Dec 11 May 7, 2027 Dec 12 May 8, 2027 Dec 13 May 9, 2027 Dec 14 May 10, 2027 Dec 15 May 11, 2027 Dec 16 May 12, 2027 Dec 17 May 13, 2027 Dec 18 May 14, 2027 Dec 19 May 15, 2027 Dec 20 May 16, 2027 Dec 21 May 17, 2027 Dec 22 May 18, 2027 Dec 23 May 19, 2027 Dec 24 May 20, 2027 Dec 25 May 21, 2027 Dec 26 May 22, 2027 Dec 27 May 23, 2027 Dec 28 May 24, 2027 Dec 29 May 25, 2027 Dec 30 May 26, 2027 Dec 31 May 27, 2027
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Last reviewed 2026-10-21. Planning tool only. Confirm pregnancies and due dates with your veterinarian. See methodology .