Vinyl Record Sizes Table
| Nominal diameter | Finished diameter | Name | RPM | Minutes per side |
|---|---|---|---|---|
| 16 in (410 mm) | 15 15/16 in ±3/32 | Transcription disc | 33 1/3 | 15 |
| 12 in (300 mm) | 11 7/8 in ±1/32 | LP (Long Play) | 33 1/3 | 22 |
| 12 in | 11 7/8 in | Maxi Single | 45 | 15 |
| 12 in | 11 7/8 in | Single (shellac era) | 78 | 4–5 |
| 10 in (250 mm) | 9 7/8 in ±1/32 | LP | 33 1/3 | 12–15 |
| 10 in | 9 7/8 in | EP (Extended Play) | 45 | 9–12 |
| 10 in | 9 7/8 in | Single (shellac era) | 78 | 3 |
| 7 in (180 mm) | 6 7/8 in ±1/32 | EP | 33 1/3 | 7 |
| 7 in | 6 7/8 in | EP | 45 | 8 |
| 7 in | 6 7/8 in | Single | 45 | 5 1/3 |
Vinyl is not one format but a family of discs defined by two numbers: diameter and speed. The chart runs from the 16-inch transcription discs made for radio stations, through the 12-inch LP (long play) at 33 1/3 rpm that defines the album, the 10-inch discs that fell between categories, down to the 7-inch single at 45 rpm that defined the jukebox and the hit parade. Each combination trades playing time against sound quality: a slower speed and a tighter groove fit more music per side but demand more from the cartridge tracking it.
The finished diameters matter more than collectors expect. A 12-inch record is never quite twelve inches - the finish cuts it to 11 7/8 inches with a plus-or-minus tolerance measured in sixty-fourths - because the trimming die and the shrink of cooling vinyl each take their share. Those millimeters decide whether an old sleeve still slides over a modern pressing, and why some import pressings bind in jackets cut to the American nominal size.
How to use
- Pick the speed by the disc, not the player: 33 1/3 is for LPs and long EPs, 45 for singles and maxis, and 78 - the pre-vinyl speed - plays only shellac-era records and needs a dedicated stylus; playing a 33 at 45 simply raises the pitch a semitone-plus and shortens the life of both record and needle.
- Estimate playing time from the chart before programming a side: about 22 minutes per side for a 12-inch LP is the classic budget, and engineers went beyond it by cutting grooves closer together - which is why loud, bass-heavy side-closers can overrun and force a shorter side order on a remaster.
- Check the finished diameter for sleeves and turntables: the nominal sizes (16, 12, 10, 7 inches) name the family, but the finished disc runs smaller (11 7/8 for 12-inch), and the tolerance band decides fit in inner sleeves, record clamps and vintage changers sized to the exact cut rather than the label.
Frequently asked questions
Why do records play at 33 1/3, 45 and 78 rpm?
Because each speed was a marketing settlement in a standards war. 78 rpm was the early twentieth-century compromise set by motor geometry and shellac durability, giving about four to five minutes per 12-inch side - one song. Columbia's 1948 vinyl LP slowed to 33 1/3 and used microgrooves to reach 22 minutes per side, inventing the album; RCA answered in 1949 with the 7-inch 45, cheaper to press and perfect for the jukebox single. The awkward 33 1/3 number is an artifact of synchronous motor and gear ratios, and the three speeds stuck because an installed base of players made every alternative uneconomic.
What is the difference between an LP, an EP and a single?
Playing time and format, not groove physics. On the chart: a 12-inch LP at 33 1/3 gives about 22 minutes per side (the album), a 12-inch maxi single at 45 gives about 15 (dance remixes and club pressings), a 10-inch EP at 45 about 9 to 12, and the 7-inch single at 45 about 5 1/3 minutes - one song per side. EP means extended play, the in-between format; on 7-inch vinyl it squeezes two songs per side at 33 1/3 or 45. The names are packaging decisions layered on the same disc-cutting technology, which is why a maxi single can be physically larger than the LP it excerpts.
Are 78 rpm records vinyl?
Almost never - they are shellac, a brittle compound of shellac resin and mineral filler, and they predate vinyl's dominance. The 78 column in the chart belongs to the pre-1950 era: roughly four to five minutes per 12-inch side, one song, heavy discs that shatter like plates. Playing them on vinyl setups damages both: shellac needs a fat, slow stylus (about 3 mil, versus under 1 mil for microgroove vinyl) and record collectors keep a separate turntable or cartridge for them. The one exception is late-era 78s pressed in vinyl during the transition years, which behave like any other record.
How does a 12-inch LP fit 22 minutes a side?
By groove geometry. The stylus reads a spiral that runs from the outer edge inward; longer playing time means the spiral turns must pack closer together (finer pitch) and the groove walls get narrower, leaving less vertical amplitude for bass and making the disc more sensitive to a worn or heavy-tracking cartridge. That is the trade the chart's minutes column summarizes: the 16-inch transcription disc held 15 minutes at broadcast fidelity, the LP stretched to 22 by microgroove engineering, and modern audiophile pressings often return to shorter sides - wider grooves, bigger bass, less music - because sound, not runtime, is what collectors are buying.