What is the difference between 33 and 45 RPM? (Answered)

There are several key differences between 33 rpm and 45 rpm records. The most notable difference is the amount of music that can be recorded on each disc.

A 45 rpm record has less capacity than a 33 rpm record because it spins faster, reducing the size of its grooves.

By the time a 33 rpm record has played for twelve minutes, a 45 rpm record is only one-third of the way through its first song. There are other less noticeable differences.

45s and 33s – How Do They Work?

A standard long play (LP) 33 1/3 RPM record can hold up to about 22 minutes worth of music on each side. If you try playing that same record at 45 RPM, it’ll only be able to hold around 7-8 minutes per side since the grooves get smaller and fit more songs per side when spinning faster. Because each revolution takes less distance than at 33 1/3 RPM, you can fit four times as many songs on a single disc if you spin it at 45 RPM.

What is the difference between 33 and 45 RPM for vinyl records?

There are several key differences between 33 rpm and 45 rpm records. The most notable difference is the amount of music that can be recorded on each disc.

A 45 rpm record has less capacity than a 33 rpm record because it spins faster, reducing the size of its grooves. 

By the time a 33 rpm record has played for twelve minutes, a 45 rpm record is only one-third of the way through its first song. There are other less noticeable differences.

A standard long play (LP) 33 1/3 RPM record can hold up to about 22 minutes worth of music on each side. If you try playing that same record at 45 RPM, it’ll only be able to hold around 7-8 minutes per side since the grooves get smaller and fit more songs per side when spinning faster.

Because each revolution takes less distance than at 33 1/3 RPM, you can fit four times as many songs on a single disc if you spin it at 45 RPM.

How to tell if your vinyl is 33, 45, or 78 rpm?

Vinyl records are measured in revolutions per minute, or RPM. They can play at three common speeds: 33 1/3, 45, and 78 RPM.

If you want a record to play at a speed other than the standard, simply select the RPM that corresponds closest to the current record playing speed.

The easiest way to find out what speeds your records can play is to look at the label of each record. It should clearly state how many RPMs it plays at as well as which speed plays side A and which plays side B.

33 rpm – Standard Play (LP) Record

The 33 1/3 rpm long-play (LP) vinyl record is considered standard because it was designed from the start for audio fidelity, unlike its predecessors, which were made to closely match the film’s pace for synchronization purposes.

When a recording studio finishes a track, they send this master disc off to production to create copies or pressings.

A copy pressed at 33 1/3 rpm is called an LP record because it’s played in 33 1/3 revolutions per minute.

45 RPM – Standard Play (LP) Record

A 45 rpm long-play (LP) vinyl record spins seven percent faster than a 33 rpm version, so its time between grooves is shorter.

This enables more audio to be crammed onto the disc which means you can fit up to fourteen minutes of material on each side.

When listening to your favorite tunes you’ll notice that some tracks sound better at the standard playback speed and others benefit from the extra juice afforded by 45s.

78 RPM – Pre-1948 Records

The earliest phonograph discs were made to play at a speed of 78 rpm.

You can tell that your record spins at this rate if the label is unnumbered, as opposed to having a 1 on one side and a 2 on the other side.

As you might expect, these discs held fewer songs than their 33 or 45 counterparts because they spun more slowly and grooves were wider and deeper to accommodate the additional grooves per inch (GPI). That means lower audio fidelity and limited volume levels – making them ideal for music boxes but not much else.

78 RPM – Post-1948 Records

Record manufacturers upped the ante by increasing playback speeds to 45 rpm after World War Two.

It made sense to make 78s spin faster since records were becoming increasingly popular with people, whose turntables were only spinning at 33 1/3 rpm.

If you’ve got a disc with information unnumbered on the label, it probably spins at 78 rpm – but be sure to check and make sure, as there are some rare exceptions.

Record Sizes and Speeds

7″-inch 33 rpm

7″-inch 45 rpm

10″ 78 rpm

12″ 33 rpm

12″-diameter 45 rpm

Other Record Dimensions and Speeds: 10 inches, 16 2/3 RPM; 14 inches, 45 RPM; 11 1/2 inches, 33 1/3 RPM. For more information about the record, sizes click here.

How to tell which speed your record is played at? What if it isn’t labeled?

The best way to find out what speeds your records can play is to look at the label of each record. It should clearly state how many RPMs it plays at as well as which speed plays side A and which plays side B. If you want a record to play at a speed other than the standard, simply select the RPM that corresponds closest to the current record playing speed.

How do I change speeds on my turntable?

It’s as easy as moving a switch to the speed you want. But make sure you move before you start the record.

This will help prolong the life of your records.

What is an LP vs EP?

LP – is a standard length for an album. It stands for Long Play and this format is used in most musical genres, including rock, pop, blues, classical, and so on.

EP – EP stands for Extended Play and it’s not common among vinyl collectors or DJs anymore. If you see this term on a cover it is an indicator that the record usually has only 4 to 5 songs since the playtime of the music was limited by one side of a 45 rpm single vinyl disc.

Conclusion

If you’re a music lover with a record player, it’s important to know the difference between 33 and 45 RPM vinyl records.

It’s not just about sound quality or how many songs you can fit on a disc – 33s and 45s have different playback speeds so you should know which one your player uses.

Otherwise, you might find yourself having to keep switching your player’s RPMs back and forth.

33 rpm vinyl records are standard commercial releases, while 45 rpm vinyl records are shorter in size for playing singles.