RPM - Turntable Speed Accuracy 4+

Real time Wow Flutter checker

Philip Broder

    • 4.4 • 1.6K Ratings
    • Free
    • Offers In-App Purchases

iPhone Screenshots


Witness the revolution, improve your sound!

Nothing beats the sound of vinyl records: drop the needle and drift away into a high-fidelity soundscape, just as the artist intended. That is, unless your record player is letting you down.

We take pride in the record collections that we’ve carefully cultivated over years, or even decades. And while the chipmunk voices and warped guitar solos may be subtle, those of us with a good ear will hear it straight away. What a waste.

This is the BEST turntable RPM speed and accuracy testing mobile app available.

See the average rpm of your turntable as well as speed variations (known as wow/flutter) in real-time graphics designed to help you find and fix errors in your setup. You won’t find an easier way to track the wow/flutter effects than the intuitive graphs presented by RPM anywhere on the market.

RPM is proud to be recommended by Rega Research Ltd, makers of some of the best turntables in world.
Great review by top tech blogger Techmoan on Youtube.
This app is even used in high end Turntable reviews in Stereophile magazine.

So how does it work?

RPM uses the gyroscope in your iPhone to determine the rotation speed of your turntable, automatically determines which speed setting you’re on, and reports how accurate it is.

Simply place your iPhone flat over the centre of the turntable platter. As the iPhone rotates the display will remain stationary from your perspective for easy reading.

The UNIQUE feature of RPM is that it shows a scrolling graph of rpm accuracy variation over time, this shows wow/flutter effects, especially those associated with the turntable not being level, belt wear or other mechanical imperfections. You can even detect the small drag caused by the stylus resting in the grooves.

And to add to all of that, you can even visualise wow and flutter variations plotted actually around the vinyl centre to show a heat map of exactly where in the turntable rotation the inaccuracies occur.

The World RPM Turntable Performance Database

We are now accepting submissions from RPM users worldwide to build the ultimate resource for researching the most accurate turntables around. Is your turntable performing as well as others of the same model? How does your turntable model compare to others available on the market? What model should you upgrade to next? All of these questions can be answered with our quickly expanding data-set.

What’s New

Version 5.9

Design and usability tweaks.
With nearly 10,000 uploads to the RPM World Database RPM is the de facto source of turntable performance and popularity.

Ratings and Reviews

4.4 out of 5
1.6K Ratings

1.6K Ratings

Miljen ,


Minor update to my previous review, and back from 5 to 4 star. I can’t understand why are variations in speed measurements between devices so great? My iPhone 8 plus show 33,40 and iPhone SE 33,31 rpm, while strobe dots on my Technics 1210 are spot on (should be 33,33). When I slow turntable a bit, so that app measures 33,33 it is clearly slow which can be seen just by observing strobe dots on the platter. Wow/flutter is ok, very low measurements ... Could the app be more precise, or is it up to the phones and OS-es?

Developer Response ,

Update: There will undoubtedly be some variation between devices due to the tolerance of the gyroscopes for which there is nothing an app can do. If you are certain that your gyro is out then you can use the calibration feature in settings to apply a fix factor to match whatever calibration device you have used, then RPM will be able to be used as is from then on.
Thanks for the 5* upgrade!!
Update: Hi Miljen, RPM is indeed calculating the w/f as the max % deviation from the average rpm. I believe the IEC spec is primarily regarding the test tone method where it applies a weighting curve to the frequency response variation, in contrast rpm is unweighted. I do know that Rega turntables use a laser etched disc and optical sensor to measure speed and w/f. There is apparently a wide range of methods amongst tt manufacturers and no strict definition of what their w/f figures represent.
Regarding the precision of rpm, my target is that rpm will enable you to setup a TT to within 0.1% of the target, i.e., 33.30-33.37, my tests indicate this is achievable, however as Apple doesn't publish the tolerance of the iPhone gyroscope I am unable to be more specific. Your measurements are well within this tolerance variation which is a good sign. I hope that helps.
Hi Miljen,
Thanks for your feedback - the screenshots aren't indicative of a 'good' turntable deliberately to show the functionality clearer. I agree that ideally you would want the w/f to be below 0.3%
If you have any suggestions for improvements please let me know directly, I'd love to earn that 5th star!

Bradbort ,

Nice, but let it run for a bit

This app is good, although I highly recommend running in calibration mode first. Before I did that on a rega rp3, it was reading way faster than the strobe disk, but once auto calibrated it was quite close. This is with an iPhone XR.

I’m still a bit confused about wow and flutter and the circular trace it does. My sense is that it it showing unevenness in rotation and platter flatness, but for wow and flutter the relevant thing is what is happening where the needle touches the record. I’m, not sure if this w&F measure is comparable to what other folks measure. I did take heart, though, that my W&F readings were generally around .2, which seems to be about what most turntables in the database show...but I have no idea if other TT measurement systems would come up with the same number.

Cr4shMyCar ,

Good, but trial is way too limited and the full version costs way too much

This app is pretty good, as far as I can tell. It’s really easy to use and doesn’t require as much effort as a stroboscope; just put your phone on a roll of tape above your turntable’s spindle and go. However, it’s extremely limited on the free version, with only 10 tests for 33 RPM and, confusingly, no way to calibrate the app. Like another reviewer said, 10 tests is just enough to potentially get you into trouble if you don’t know what you’re doing. I have no qualms with paying for a good app, but 15 dollars for the full version is way too much for an app I’d rarely use. If you aren’t constantly adjusting the speed on turntables, just print out a stroboscope disk and get a stroboscope app. It takes a little more effort but it’s completely free.

App Privacy

The developer, Philip Broder, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Identifiers
  • Usage Data
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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