33⅓ and 45 are the speeds, in revolutions per minute, that a record is cut to play at: albums are usually 33⅓, 7-inch singles 45, and 12-inch singles, common in dance music, often 45. A 45 gives the cutting engineer more groove per second for detail and level, while a 33⅓ fits far more music on a side, and the mastering matters more than the speed.
What the numbers mean
RPM is how many times the record turns in a minute. A record has to be played at the speed it was cut at: played at 45, a 33⅓ record runs about a third too fast and sounds high and hurried; played at 33⅓, a 45 sounds slow and low. DJ turntables have buttons for both, and some add 78, which Technics' manual uses for SP records.
Check the label and the sleeve for the speed. If neither gives it, play a few seconds at 33⅓: a voice that sounds too deep and slow means the record is a 45.
Sizes, speeds and how much each side holds
Records are pressed in 7-inch, 10-inch and 12-inch sizes, and any size can be cut at either speed, but the faster speed holds less music because the groove runs past the stylus faster. United Record Pressing, a US pressing plant, publishes its suggested maximum playing time per side:
| Size | 33⅓ rpm | 45 rpm | 78 rpm |
|---|---|---|---|
| 7-inch | 8 minutes | 6 minutes | 3 minutes |
| 10-inch | 13 minutes | 8 minutes | 6 minutes |
| 12-inch | 22 minutes | 13 minutes | 11 minutes |
Going over those times means packing the grooves closer together and cutting the bass or the overall level, which United Record Pressing says makes for noisier records with weaker bass. Other plants give slightly different figures.
Dance music needs even less per side. Diggers Factory, a vinyl production company, recommends about 11 minutes 27 seconds for a 12-inch at 33 and 8 minutes 28 seconds at 45 for dance, techno, electro and rap, against about 19 and 14 minutes for rock and pop. It notes that the 12-inch 45, which allows one track a side with the grooves spread as wide as possible, has been used a lot in electronic music and is popular with DJs.
Does a 45 sound better than a 33
It can. Paul McGowan of the audio maker PS Audio sets out the mechanical argument: at 45 the groove moves past the stylus faster, so more high-frequency detail can be cut without the groove getting too steep for the cartridge to track. The inside of each side gains most. The innermost grooves are smaller, so the groove passes the stylus more slowly there, and United Record Pressing warns that long sides risk distortion and lost high frequencies near the label.
The cost is playing time: an album that fits on one 33⅓ record needs two at 45. McGowan's conclusion is that a well-mastered 33⅓ can beat a poorly mastered 45, and that mastering matters more than speed. For a DJ, the practical gain of a 12-inch 45 is a louder, wider-cut track on a side of its own.
Record weight
A standard 12-inch record weighs about 140 grams, and 180 grams is the common heavyweight option, per the pressing broker Disc Makers; a 7-inch averages about 40 grams. Disc Makers says a 180 g record is pressed with the same stampers and groove depth as a 140 g one and should sound identical on most turntables, though the extra mass can damp small vibrations on high-end systems. Standard Vinyl, a Canadian plant, says a heavier record is more durable.
Setting the speed on a DJ deck
On the Technics SL-1200MK7, per its owner's manual:
- Switch on. The deck selects 33⅓ automatically and the [33] button lights.
- For a 45, press [45]. For EP records, fit the EP record adaptor that comes in the box over the centre spindle.
- For 78, first enable it with the 78 rpm setting switch (switch no. 4), then press [33] and [45] together.
- Press [RESET] to lock the platter to exact speed, or turn RESET off and use the PITCH ADJ fader, with a range of about ±8% or ±16%, chosen with the pitch range button.
The strobe dots around the platter's edge check the speed: one row appears to stand still at exactly 33⅓, 45 or 78, and the other rows at set pitch changes. The Reloop RP-7000 MK2 works the same way: 33 and 45 switches, both pressed together for 78, and a pitch range of ±8%, ±16% or ±50% (Reloop manual). PLX-1000 vs Technics 1200 and the best DJ turntables compare decks.
Speed with control vinyl and motorised controllers
With a digital vinyl system, the control record's speed tells the software how fast to play the track, so the deck and the software have to agree. In Serato DJ Pro, Setup > DJ Preferences > Virtual Deck Speed switches between 33 and 45 RPM, and Serato notes that 45 uses more processing power and can cause dropouts on slower computers. The DVS guide covers the setup.
Motorised controllers have the same two speeds. The Rane Twelve MKII has 33 and 45 buttons for its 12-inch control disc (user guide), and the DDJ-REV7 has 33 and 45 buttons for its platters (manual). The jog wheel guide explains how those platters work.
How this page is made
Speeds, playing times and weights come from pressing plants and a pressing broker (United Record Pressing, Diggers Factory, Standard Vinyl and Disc Makers), the sound argument from PS Audio, and the deck controls from the Technics, Reloop, Rane, Pioneer DJ and Serato manuals, all read on 13 October 2026 and linked where they are used. Plants set their own limits, so check yours before cutting a record. We haven't tested these turntables. The methodology explains how the site works.
