What the numbers mean
RPM means revolutions per minute: how many times the platter turns in a minute. A record has to be played at the speed it was cut at, otherwise both the tempo and the pitch change. The U.S. National Archives' list of recording speeds, used to catalogue audio disks, includes 16, 33⅓, 45 and 78 RPM among its values.
| Speed | Typical records | What to watch |
|---|---|---|
| 33⅓ RPM | LPs, usually 12-inch; some 10-inch records | The default on most turntables |
| 45 RPM | Most 7-inch singles, many 12-inch singles and some audiophile LP reissues | Large-hole singles need the 45 adapter |
| 78 RPM | Older records, often shellac, usually 10-inch | Needs a 78 setting and suitable stylus |
How to tell which speed a record needs
Read the label
Most labels print 33, 33⅓, 45 or 78, sometimes as LP or RPM. Check both sides: a few records use different speeds per side.
Check the sleeve
If the label is silent, the back of the sleeve or the insert often states the speed.
Start at 33⅓
For a 12-inch record with no marking, begin at 33⅓. If voices sound slow, low and dragging, switch to 45.
Trust your ears with singles
A 7-inch single is very likely 45. If singers sound high and rushed at 45, try 33⅓; some small records were cut at that speed.
The 45 adapter and large-hole singles
Many 7-inch singles have a large centre hole, originally designed for jukeboxes and record changers. To play one on a normal spindle, put the small 45 adapter on the spindle first. The Audio-Technica AT-LP8X manual lists a 45 RPM adapter in the box and tells you to attach it when playing 45 RPM records.
Some turntables, like the AT-LP60-BT, also have a size selector for 12-inch and 7-inch records so the automatic arm lands in the right place. Set both size and speed before you press start.
78s are a special case
Records from the first half of the twentieth century were often made of shellac, not vinyl, and turned at around 78 RPM. Only some modern turntables offer a 78 setting; the AT-LP8X does, many others stop at 33⅓ and 45.
Early 78s were not always made at exactly 78. The Discography of American Historical Recordings notes that early studios kept no written record of their turntable speeds and that a difference of 4 RPM shifts the pitch by a half tone. An IASA workshop at the Library of Congress was devoted to choosing stylus size and speed for acoustic-era 78s, because archivists still have to work them out from the discs.
Different speeds, different sizes on the shelf
Speed usually goes hand in hand with size, and size matters for storage. The Library of Congress advises against storing grooved discs of different diameters together and recommends shelving them upright with firm dividers. In practice that means separate sections or boxes for 7-inch singles, 10-inch records and 12-inch LPs, so small discs do not slip between large ones and press against their surfaces.
If you keep 78s, give them their own shelf as well: they are heavier, often more fragile and should not lean on vinyl. Our guide on storing vinyl records covers shelves, dividers and climate.
Right setting, wrong speed?
Choosing 33⅓ or 45 is only half of it. A worn belt, a dirty pulley or a turntable that is not level can make the platter turn slightly too fast or too slow, so music sounds a little sharp, flat or wobbly even at the correct setting.
Our guide on checking turntable speed with your phone shows a quick way to estimate it. For a precise measurement, use a strobe disc or a dedicated test record.