Assuming you are fit for the longer distance being compared, the following chart should enable you to predict an expected time for one distance based on your best recent time for another distance:
3000 5000 10000 1/2Mar Marathon
9.45 16.40 34.30 77.00 2:41.30
10.00 17.05 35.20 78.50 2:45.20
10.15 17.30 36.10 80.40 2:49.10
10.30 17.55 37.00 82.30 2:53.00
10.45 18.20 37.50 84.20 2:56.50
11.00 18.45 38.40 86.10 3:00.40
11.15 19.10 39.30 88.00 3:04.30
11.30 19.35 40.20 89.50 3:08.20
11.45 20.00 41.10 91.40 3:12.10
12.00 20.25 42.00 93.30 3:16.00
12.15 20.50 42.50 95.20 3:19.50
12.30 21.15 43.40 97.10 3:23.40
12.45 21.40 44.30 99.00 3:27.30
13.00 22.05 45.20 1:40.50 3:31.20
13.15 22.30 46.10 1:42.40 3:35.10
13.30 22.55 47.00 1:44.30 3:39.00
13.45 23.20 47.50 1:46.20 3:42.40
14.00 23.45 48.40 1:48.10 3:46.30
14.15 24.10 49.30 1:50.00 3:50.20
14.30 24.35 50.20 1:51.50 3:54.10
14.45 25.00 51.10 1:53.40 3:58.00
15.00 25.25 52.00 1:55.30 4:01.50
15.15 25.50 52.50 1:57.20 4:05.40
15.30 26.15 53.40 1:59.10 4:09.30
15.45 26.40 54.30 2:01.00 4:13.20
16.00 27.05 55.20 2:02.50 4:17.10
3000 5000 10000 1/2Mar Marathon
9.45 16.40 34.30 77.00 2:41.30
10.00 17.05 35.20 78.50 2:45.20
10.15 17.30 36.10 80.40 2:49.10
10.30 17.55 37.00 82.30 2:53.00
10.45 18.20 37.50 84.20 2:56.50
11.00 18.45 38.40 86.10 3:00.40
11.15 19.10 39.30 88.00 3:04.30
11.30 19.35 40.20 89.50 3:08.20
11.45 20.00 41.10 91.40 3:12.10
12.00 20.25 42.00 93.30 3:16.00
12.15 20.50 42.50 95.20 3:19.50
12.30 21.15 43.40 97.10 3:23.40
12.45 21.40 44.30 99.00 3:27.30
13.00 22.05 45.20 1:40.50 3:31.20
13.15 22.30 46.10 1:42.40 3:35.10
13.30 22.55 47.00 1:44.30 3:39.00
13.45 23.20 47.50 1:46.20 3:42.40
14.00 23.45 48.40 1:48.10 3:46.30
14.15 24.10 49.30 1:50.00 3:50.20
14.30 24.35 50.20 1:51.50 3:54.10
14.45 25.00 51.10 1:53.40 3:58.00
15.00 25.25 52.00 1:55.30 4:01.50
15.15 25.50 52.50 1:57.20 4:05.40
15.30 26.15 53.40 1:59.10 4:09.30
15.45 26.40 54.30 2:01.00 4:13.20
16.00 27.05 55.20 2:02.50 4:17.10
