Rat Gestation Chart and Table

Every fifth breeding date across the year with the matching birthing date, calculated at 22 days. The normal range is 21 to 23 days, so treat each due date as the middle of a window. The page is formatted to print cleanly for a barn wall.

Rat gestation table: breeding to birthing dates

Rat breeding dates at five-day intervals with calculated birthing dates
Breeding dateExpected birthing date (22 days)
1 Jan 202623 Jan 2026
6 Jan 202628 Jan 2026
11 Jan 20262 Feb 2026
16 Jan 20267 Feb 2026
21 Jan 202612 Feb 2026
26 Jan 202617 Feb 2026
31 Jan 202622 Feb 2026
5 Feb 202627 Feb 2026
10 Feb 20264 Mar 2026
15 Feb 20269 Mar 2026
20 Feb 202614 Mar 2026
25 Feb 202619 Mar 2026
2 Mar 202624 Mar 2026
7 Mar 202629 Mar 2026
12 Mar 20263 Apr 2026
17 Mar 20268 Apr 2026
22 Mar 202613 Apr 2026
27 Mar 202618 Apr 2026
1 Apr 202623 Apr 2026
6 Apr 202628 Apr 2026
11 Apr 20263 May 2026
16 Apr 20268 May 2026
21 Apr 202613 May 2026
26 Apr 202618 May 2026
1 May 202623 May 2026
6 May 202628 May 2026
11 May 20262 Jun 2026
16 May 20267 Jun 2026
21 May 202612 Jun 2026
26 May 202617 Jun 2026
31 May 202622 Jun 2026
5 Jun 202627 Jun 2026
10 Jun 20262 Jul 2026
15 Jun 20267 Jul 2026
20 Jun 202612 Jul 2026
25 Jun 202617 Jul 2026
30 Jun 202622 Jul 2026
5 Jul 202627 Jul 2026
10 Jul 20261 Aug 2026
15 Jul 20266 Aug 2026
20 Jul 202611 Aug 2026
25 Jul 202616 Aug 2026
30 Jul 202621 Aug 2026
4 Aug 202626 Aug 2026
9 Aug 202631 Aug 2026
14 Aug 20265 Sept 2026
19 Aug 202610 Sept 2026
24 Aug 202615 Sept 2026
29 Aug 202620 Sept 2026
3 Sept 202625 Sept 2026
8 Sept 202630 Sept 2026
13 Sept 20265 Oct 2026
18 Sept 202610 Oct 2026
23 Sept 202615 Oct 2026
28 Sept 202620 Oct 2026
3 Oct 202625 Oct 2026
8 Oct 202630 Oct 2026
13 Oct 20264 Nov 2026
18 Oct 20269 Nov 2026
23 Oct 202614 Nov 2026
28 Oct 202619 Nov 2026
2 Nov 202624 Nov 2026
7 Nov 202629 Nov 2026
12 Nov 20264 Dec 2026
17 Nov 20269 Dec 2026
22 Nov 202614 Dec 2026
27 Nov 202619 Dec 2026
2 Dec 202624 Dec 2026
7 Dec 202629 Dec 2026
12 Dec 20263 Jan 2027
17 Dec 20268 Jan 2027
22 Dec 202613 Jan 2027
27 Dec 202618 Jan 2027

How to read the rat gestation chart

Find the row closest to the date the rat was served. The right-hand column is the expected birthing date at 22 days. Because normal gestation spans 21 to 23 days, plan for a window of a few days either side of that date. For a date that is not on the grid, use the calculator below.

Look up an exact rat due date

Estimated birthing date

Monday, 24 August 2026

Earliest

23 Aug 2026

Latest

25 Aug 2026

Printable rat gestation calendar

The table above is formatted for paper: navigation, buttons and adverts are hidden when printed, so it comes out as a clean one-page calendar for the barn wall or breeding record.

Rat gestation chart FAQs