I've found a samll range of factors (1.35 to 1.45) multiplied by 600m time predicts 800m time well for most runners; 1.40 being the mid-range factor, which I use the most.
Below are times using just the 1.40 factor. I hope it helps runners in some way!
Tinman's 600m to 800m Coversions
600m ------------ Conversion------------ 800m
Time ------------ Factor ------------ Time
1:12.00 ------------ 1.40 ------------ 1:40.80
1:13.00 ------------ 1.40 ------------ 1:42.20
1:14.00 ------------ 1.40 ------------ 1:43.60
1:15.00 ------------ 1.40 ------------ 1:45.00
1:16.00 ------------ 1.40 ------------ 1:46.40
1:17.00 ------------ 1.40 ------------ 1:47.80
1:18.00 ------------ 1.40 ------------ 1:49.20
1:19.00 ------------ 1.40 ------------ 1:50.60
1:20.00 ------------ 1.40 ------------ 1:52.00
1:21.00 ------------ 1.40 ------------ 1:53.40
1:22.00 ------------ 1.40 ------------ 1:54.80
1:23.00 ------------ 1.40 ------------ 1:56.20
1:24.00 ------------ 1.40 ------------ 1:57.60
1:25.00 ------------ 1.40 ------------ 1:59.00
1:26.00 ------------ 1.40 ------------ 2:00.40
1:27.00 ------------ 1.40 ------------ 2:01.80
1:28.00 ------------ 1.40 ------------ 2:03.20
1:29.00 ------------ 1.40 ------------ 2:04.60
1:30.00 ------------ 1.40 ------------ 2:06.00
1:31.00 ------------ 1.40 ------------ 2:07.40
1:32.00 ------------ 1.40 ------------ 2:08.80
1:33.00 ------------ 1.40 ------------ 2:10.20
1:34.00 ------------ 1.40 ------------ 2:11.60
1:35.00 ------------ 1.40 ------------ 2:13.00
1:36.00 ------------ 1.40 ------------ 2:14.40
1:37.00 ------------ 1.40 ------------ 2:15.80
1:38.00 ------------ 1.40 ------------ 2:17.20
1:39.00 ------------ 1.40 ------------ 2:18.60
1:40.00 ------------ 1.40 ------------ 2:20.00
1:41.00 ------------ 1.40 ------------ 2:21.40
1:42.00 ------------ 1.40 ------------ 2:22.80
1:43.00 ------------ 1.40 ------------ 2:24.20
1:44.00 ------------ 1.40 ------------ 2:25.60
1:45.00 ------------ 1.40 ------------ 2:27.00
1:46.00 ------------ 1.40 ------------ 2:28.40
1:47.00 ------------ 1.40 ------------ 2:29.80
1:48.00 ------------ 1.40 ------------ 2:31.20
1:49.00 ------------ 1.40 ------------ 2:32.60
1:50.00 ------------ 1.40 ------------ 2:34.00
1:51.00 ------------ 1.40 ------------ 2:35.40
1:52.00 ------------ 1.40 ------------ 2:36.80
1:53.00 ------------ 1.40 ------------ 2:38.20
1:54.00 ------------ 1.40 ------------ 2:39.60
1:55.00 ------------ 1.40 ------------ 2:41.00
1:56.00 ------------ 1.40 ------------ 2:42.40
1:57.00 ------------ 1.40 ------------ 2:43.80
1:58.00 ------------ 1.40 ------------ 2:45.20
1:59.00 ------------ 1.40 ------------ 2:46.60
2:00.00 ------------ 1.40 ------------ 2:48.00
2:01.00 ------------ 1.40 ------------ 2:49.40
2:02.00 ------------ 1.40 ------------ 2:50.80
2:03.00 ------------ 1.40 ------------ 2:52.20
2:04.00 ------------ 1.40 ------------ 2:53.60
2:05.00 ------------ 1.40 ------------ 2:55.00
2:06.00 ------------ 1.40 ------------ 2:56.40
2:07.00 ------------ 1.40 ------------ 2:57.80
2:08.00 ------------ 1.40 ------------ 2:59.20
2:09.00 ------------ 1.40 ------------ 3:00.60
---------------------------------------------------------
Regards,
Tinman