Amount of tape on a spool

Background

This page describes the different amounts of tape on a spool.
Smaller reels mean smaller machines can be made, especially for portable machines. Small reels were also used for posting voice messages round the world, at the time this was much cheaper than international calls as well as something to keep.
Larger reels require much bigger machines but also allow faster tape speeds for quality. Studio machines are very heavy for stability and this larger reels were not a transport problem and also gave longer recording time.

Reel size Inches	Tape type	Tape length
		Feet	Meters
3 cine	Standard	150	45
	Long Play	225	67.5
	Double Play	300	90
	Tripple Play	450	135
3.25 cine	Standard	200	60
	Long Play	300	90
	Double Play	400	120
	Tripple Play	600	180
4 cine	Standard	300	90
	Long Play	450	135
	Double Play	600	180
	Tripple Play	900	270
4.25 cine	Standard	400	120
	Long Play	600	180
	Double Play	900	270
	Tripple Play	1200	360
5 cine	Standard	600	180
	Long Play	900	275
	Double Play	1200	360
	Tripple Play	1800	550
5.75 cine	Standard	900	275
	Long Play	1200	360
	Double Play	1800	550
	Tripple Play	2400	720
7 cine	Standard	1200	365
	Long Play	1800	550
	Double Play	2400	738
	Tripple Play	3600	1100
8.25 cine	Standard	1800	550
	Long Play	2400	720
	Double Play	3600	1100
	Tripple Play	4800	1440
8 NAB	Standard
	Long Play
	Double Play
	Tripple Play
10.5 NAB	Standard	2400	720
	Long Play	3600	1100
	Double Play	4800	1440
	Tripple Play	7200	2200
12 NAB	Standard
	Long Play
	Double Play
	Tripple Play
14 NAB	Standard	4800	1440
	Long Play	7200	2200
	Double Play	9600	2880
	Tripple Play	14200	4400

Notes:

Some spools have smaller centre diameters allowing slightly more tape on the spool than normal.