Sound speed is normally 24 fps (Frames per Second), silent speed for older films is 16 fps, for later films is 18 fps.

A 50 ft reel is 2.8 inches in diameter.
A 100 ft reel is 3.6 inches in diameter.
A 200 ft reel is 5 inches in diameter.
A 300 ft reel is 5.75 inches in diameter.
A 400 ft reel is 7 inches in diameter.
A 600 ft reel is 9.25 inches in diameter.
An 800 ft reel is 10.5 inches in diameter.
A 1200 ft reel is 12.25 inches in diameter.
A 1600 ft reel is 13.75 inches in diameter.
A 2000 ft reel is 15 inches in diameter.
A 2300 ft reel is also 15 inches in diameter, but with a smaller hub.

Once you know about how much film is on the reel, you can estimate the running time below.
 

16 mm

Regular 8 mm

Super 8 mm

16mm - 40 frames per foot
	24 fps		18 fps		16 fps
ft	min	sec	min	sec	min	sec
100	2	47	3	42	4	10
200	5	33	7	24	8	20
300	8	20	11	7	12	30
400	11	7	14	49	16	40
500	13	53	18	31	20	50
600	16	40	22	13	25	0
700	19	27	25	56	29	10
800	22	13	29	38	33	20
900	25	0	33	20	37	30
1000	27	47	37	2	41	40
1100	30	33	40	44	45	50
1200	33	20	44	27	50	0
1300	36	7	48	9	54	10
1400	38	53	51	51	58	20
1500	41	40	55	33	62	30
1600	44	27	59	16	66	40
1700	47	13	62	58	70	50
1800	50	0	66	40	75	0
1900	52	47	70	22	79	10
2000	55	33	74	4	83	20
2100	58	20	77	47	87	30
2200	61	7	81	29	91	40
2300	63	53	85	11	95	50
2400	66	40	88	53	100	0

Regular 8mm - 80 frames per foot
	24 fps		18 fps		16 fps
ft	min	sec	min	sec	min	sec
100	5	33	7	24	8	20
200	11	7	14	49	16	40
300	16	40	22	13	25	0
400	22	13	29	38	33	20
500	27	47	37	2	41	40
600	33	20	44	27	50	0
700	38	53	51	51	58	20
800	44	27	59	16	66	40
900	50	0	66	40	75	0
1000	55	33	74	4	83	20
1100	61	7	81	29	91	40
1200	66	40	88	53	100	0
1300	72	13	96	18	108	20
1400	77	47	103	42	116	40
1500	83	20	111	7	125	0
1600	88	53	118	31	133	20
1700	94	27	125	56	141	40
1800	100	0	133	20	150	0
1900	105	33	140	44	158	20
2000	111	7	148	9	166	40
2100	116	40	155	33	175	0
2200	122	13	162	58	183	20
2300	127	47	170	22	191	40
2400	133	20	177	47	200	0

Super 8mm - 72 frames per foot
	24 fps		18 fps
ft	min	sec	min	sec
100	5	0	6	40
200	10	0	13	20
300	15	0	20	0
400	20	0	26	40
500	25	0	33	20
600	30	0	40	0
700	35	0	46	40
800	40	0	53	20
900	45	0	60	0
1000	50	0	66	40
1100	55	0	73	20
1200	60	0	80	0
1300	65	0	86	40
1400	70	0	93	20
1500	75	0	100	0
1600	80	0	106	40
1700	85	0	113	20
1800	90	0	120	0
1900	95	0	126	40
2000	100	0	133	20
2100	105	0	140	0
2200	110	0	146	40
2300	115	0	153	20
2400	120	0	160	0

Copyright 2004, Paul Ivester
You may make copies of this for your personal use, for other uses, please contact me for permission.

Return to Paul's Film Collecting Page

Return to the School Film Archives Page