are key sizes on digital pianos same/similar to real piano keys?

I can categorically say that the size between acoustics and digital pianos is not 100% the same.
I know this because I have measured the size of the following DPs;
Yamaha P515
Roland HP605
Casio PXS3000
Studiologic Grand
Roland FP30
Kawai VPC1

Apart from the VPC, HP605 and SL Grand the others were ever so slightly smaller on the width and length (not by much though) around 1-2 mm. A small difference? Sure, BUT I certainly noticed it when playing deep into the keys between the black keys it felt less roomy and probably as I have long fingers and on the larger side size hands (for example I can just about span a 10th interval). Perhaps people with smaller hands might be inclined to not feel the subtle difference.

Now, unfortunately I’ve only played a handful acoustics, a Yamaha U and B series, a Bechstein baby grand and lastly a ritmuller. The Yamaha B felt more akin to the Yamaha P515 in that the space for my fingers between the black keys felt smaller but the rest did not.
As a conclusion, I’d say that the VPC1 feels a lot more similar to an acoustic piano like the Yamaha U and the Bechstein than all the other DPs.

I'm not claiming they are 100% the same size, that would be weird. I hope the OP can find a shop that can fullfil his demonstration requirements. The weighting and speed of action would be the interesting difference.

Presumably the better the key action the easier the trill. I understand some of the cheaper triple sensor keyboards are no better than high quality double sensor models. If the mechanical weighting of the keys produces too slow a return action I guess that triple sensors on cheaper models is purely academic.

As someone with smaller hands I would suggest a very slightly narrower key could actually be preferable. OTOH black keys that are too narrow or with tops that are too rounded are more slippy and awkward to play. Though this has been more of an issue on smaller MIDI controllers.

Small hands.
https://paskpiano.org/hand-span-data-old/

Relatively speaking it's minutiae. The one size fits all aspect of piano design is quite ridiculous. The differences in real world hand span is dramatic, even my two hands are different to each other!

The differences in key length, width, size and spacing between keyboards is miniscule compared to what it should really be. I can pretend to have Rachmaninoff hand span with some synth action keyboards - trouble is they lack the correct action so velocity response dynamics is all over the place. 

Another page dedicated to those of us that are digitally challenged (in the finger sense)!
https://www.musicalhow.com/piano-for-small-hands/

A note on the SL88 but let me start with the kawai first.

I tried the ES8 a few years ago and I recall the keys were slim I assume the MP7se sharing the same action will be the same. Apart from that, it was decent albeit light in comparison to an acoustic.
I used to own the SL88 grand and whilst the keys are larger the two sensor makes it feel an upright than a grand and I do mean that, getting repeated notes you had better adjust your technique to allow for that key to return as close to its up position. Hence why I got rid of it..

It has according to their spec. I stand corrected, but it feels like nothing like the other triple sensors that I personally tried and have spend a great deal of time and money on many DPs.

That's good to know, but maybe there's more to the key action than that?

That's the sort of information people want though.  I think Woody (in the video) implied that the action was the same as the FP range (though I wasn't expecting the same as the FP90 mentioned at the beginning of the thread), and I have assumed that the equivalent digital piano (from the same manufacturer) would cost more though.

I guess economies of scale again - what percentage of people actually want affordable digital pianos Vs high end pure MIDI controllers?

Personally so long as a digital piano was significantly better value I would rather buy that and ignore the internal sounds completely. So long as it outputs MIDI over USB. I would rather pay less for a pure controller though. From the hardware perspective it only seems logical - when you buy less you should get to pay less. As we know it doesn't always work that way.

Edit: FP10  can be had for around half the price of A88 MK2. If the key action really is the same as the A88 Mk2 and if it puts out MIDI over USB that's a helluva saving. If you want additional pedals that can be done for far less with extra USB MIDI inputs. Pitch bend, modulation etc can be done with extra controllers for less pennies. That's if the keyboard is the main concern.

Hopefully I'm not monopolising the OPs thread, and he considers this still on topic.
If I can get the same quality in a slightly less fancy package that's how I would prefer to spend my money. It's more hassle though.

Not bothered either way about high resolution MIDI of the A88 Mk2.
127 regular MIDI steps of most keyboards probably already offers more than enough fine resolution for all the tonal differences we could discern. Fine if it's got it as a feature but by contrast an even better mechanical action I would expect to make a real world tangible or perceptible difference.

I heartily second everything Nathan said.

I would add that differences in action regulation (as opposed to design) can also alter the relative position of keys.  Sometimes the key top difference between the black keys and the white keys varies slightly between makers (less then a mm or two but enough to notice) and sometimes within the same instrument; I remember one incident in particular where an otherwise excellent piano "peaked" 2mm higher on the white key tops at the center of the instrument and sagged 2mm at both extremes of the piano, which was a regulation (or rather mis-regulation) byproduct.  Another instrument had been regulated to have the black keys 0.5mm to 1mm higher than "standard" and the entire instrument had to be regulated again to fix it.  Key weight is also as much a factor of regulation as it is of design--since good regulation allows a technician to target the usual 50 gram drop weight (with equally important lift weight being its own art form--and nightmare), but as an action falls out of regulation--just as the instrument falls out of tune, keys will stiffen or loosen with significant variation across the instrument.  Sadly, I've noticed several "big name" piano makers for both acoustics and digitals try to get out ahead of the eventuality of pianos losing their regulation with time and stiffen the keys to 65g and even 75g which is just brutal, especially as their instruments are frequently marketed to students and educational institutions.

On the highest-end digital instruments ($2K USD and up) from Casio/Bechstein, Yamaha, Kawai, etc., you'll find extremely close similarity in design between the digital action and that manufacturer's acoustic action.  It's important to further consider that key stick length (including the part of the key that continues behind the fallboard) is very different between European and East Asian piano makers and significantly impacts the "feel" of an instrument.  East Asian companies, like Kawai, favor longer key sticks which creates a very balance point for the key, and their digitals reflect that.  (Kawai is especially notorious for this--and they pride themselves on this distinction in their marketing literature--since their carbon fibre/abs plastic actions require more wood in the key stick through greater length to create the same balanced feel that a wood action has, but it always feels off to me.)  I was amazed at the difference in feel between a Millenium III Action Kawai next to a 1920s Bechstein--the two had entirely different responses because of action weight and key stick length (with the Bechstein feeling like it were half the length of key stick), despite having generally similar key dimensions.

I particularly agree with Nathan that US halls--being predominantly Steinway, Yamaha, and Kawai (in that order), have little to no variation in feel and texture between pianos, which on the one hand offers the comfort of consistency for performers and--on the other hand--impinges on creative exploration of new textures during performances that would be offered by access to the broader range of piano maker history.  That said, a Steinway Model A from around 1906 had the smallest keys I've ever encountered, bringing the octave substantially smaller (I can reach any 10th and occasionally an 11th but on this I believe I could reach around a 14th) but it had the most beautiful sound of any small piano I've encountered in my life!

And, yes, key edges on lower-quality acoustics can be sharp enough to draw blood--ask me how I know...

oh, that's a great advice!
i will check them out. never been to Milton Keynes, so i just turn it into a daytrip ;-)

Thanks for the interesting video link.

The more I think about the piano world today the more odd this problem seems.

Feminism and equal opportunities perhaps don't fit into the conservative world of classical music, or serious jazz?

The popularity of acoustic piano in the home has fallen off a cliff in the west. I suggest much more girls learn serious classical music than boys today, and Asians make up the lion's share of real acoustic piano customers. Also the Asian families take this very seriously and start their children at a very young age.

So statistically I would expect the vast majority of serious pianists hands are poorly served by the standard today.

However even historically western men were also smaller than they are today. A number of the great composers were actually small for their time.
  So I imagine more tall young men have larger hands than ever before but  they don't make up the majority of pianists.

Of course players have obviously worked around these issues but it's pretty clear that this is injuring people!

Perhaps more people would have taken up piano, or stayed with it if the physical difficulty was lessened?

A video player that says "not available in your country" ?

I stumbled about this topic a few weeks ago and did a lot of investigation. Besides the size of the keys the layout is not ergonomic. I ended up buying a Linnstrument. My opinion is that the instrument is just a tool for making music but not its source. I would have also bought a digitalpiano with key size of 6"/Oct which would fit much better to my not so big hands. I was just sick of constantly playing hard mode due to not having hands like Rachmaninoff...

Actually I would like to buy a Janko Piano
https://youtu.be/cb67ykXJc8o

Are there any virtuoso recordings with these alternative layout keyboards?

Maybe that belongs in its own separate thread then.
It could be interesting. Alternative controllers have been something I've looked at in the last few years.

Slightly slimmer keyboards aren't such a divergence from what we know today. I can see those potentially making a real difference in the market, with the right backers, brave investors and so on. Promoted well I think it could actually boost sales of pianos and keyboards.
Less so the alternative keyboard layouts - however logical, anatomically friendly or capable the designs.

This is why I decided to buy a Linnstrument. If I could afford it the Lumatone would be definately my first choice.

As a 'small-handed' person, I see benefits for narrow keys for current music, but in another few decades, large-handed composers will then have even greater note span in their new works, as they themselves use the narrower-key keyboards.

So here comes a different layout into account. It is everybody's own preference if he wants to use a tool as good as possible or just wants to make music. For me music doesn't become worse only because I won't use the original instrument it was written for.

Then narrowed narrow keyboards will be made so that small-handed people can play these XXL span pieces, and so on ...
So by the end of the century the only limit will be the width of the pianists' fingers...

Totally agree, and being myself a rather small handed people I would like to own such a shrunken keyboard !

Not among the brands you mentioned, but I can tell you that the size and weight of the keys on my Native Instruments Komplete Control S88 MK2 are virtually identical to our Steinway. Even measuring the entire length of the 88 keys is within 1/8 inch.

Good to see that image, thanks David. Hoping that keyboard maker grows and grows.. I like it.

I had seen that video "Piano's Darkest Secret" by MusicalBasics, posted by Don above. Loved the idea of smaller key size for smaller hands - and it struck me as strange that makers of those boards with smaller keys are not more well known.

But I suppose it's just so cemented in, that piano keys are of a particular size for various reasons.

It would be impossible for all concert halls to offer performers a choice of pianos (like maybe they have 1 or 2 house pianos which have to suit all performers without the expense of shipping in specific ones).. other reasons..

Like schools of all kinds, teaching kind of standardizing on many things, I guess, if they can graduate students who are 'ready' for concert halls and normal pianos in most situations, it would be currently obvious that teaching on one standard size could be seen, by students/parents/mentors etc., as being the 'rational' thing to do.

But, for sure any musician at the skill level they are happy with can surely choose and use any instrument, size etc. for fun or professional reasons too. (esp. outside classical piano context).

I do think we can blame the incredibly ingrained an difficult to shift 'concert hall' background for most orchestra related instrumentation, regulations and right down to sizing of things like keys on pianos. There's reason for all of that - expense. It's not incorrect or a bad history of awful decisions when you think on it. Things like making certain orchestras standardize on a certain frequency measure of the note A.. whatever these things in the past really meant, "If you want to sell pianos to orchestras, you better make the diapason at this measurement.. the keys the same as they always were so nobody has to adjust" (or ... maybe nobody every mentioned key size at all.. it's one of the things just taken to be a default.. because all early pianos were trying to find ways to make "BIGGER" pianos, with more notes, for Beethoven! and his ilk. Smaller keys would NOT have been an advantage in the era where composers where demanding bigger, louder, more notes. A lot of fortepiano structures were small.. I can imagine piano makers hearing Beethoven demands more, would be thinking.. "What if we made our keys larger, strings further apart.. then we would have reason for larger frame.. and less cramped parts will sing better." _ IDK for sure what they would have considered of course - but if 'the market' wants 'huge', few engineers might say "What if we made smaller keys!".. "You're fired!"

Interesting that I know, if I were younger I'd go running to the music store to try out a Roly Seaboard.. love the idea of breaking out of 'old ways' personally for my own music but I know it would be taking me nowhere if my goal was to play standard classical repertoire in concert settings, which is probably where most kids and parents begin from when putting their children into piano classes (where the cementing in of standards all begins).

A typical music store lives or dies from having or not having school supply contracts, to deliver a fairly predictable number of instruments to as many schools as they can sign up.. who in their right mind in a music store would say to a school.. "Hey you guys, we're taking delivery of this consignment of a new piano type.. with small keys and we think your kids are going to work well with it - how many do you want to order today?".

Maybe though, that's ALL it would take.. get a smaller key piano into schools.. could be cheaper than supplying "big adult" sized ones. ?? Would need a push - a complete billionaire-like setup to flood the entire western "school music supply". Maybe a consortium of music equipment distribution companies could work with some major countries' government (politicians responsible for arts portfolios etc.) - make a set of draft resolutions 'to overhaul piano related supply considerations'.. years later.. one by one, fill some large contracts to some large schools who 'signed on' to the resolution through whatever governable processes they use to interface with government.. years later again.. maybe there'd be an acceptable 2 tiers of piano size. The savings made in school venues (buying smaller/cheaper pianos) might be recouped by manufacturers/distributors in the later supply chains, where they may deliver 2 pianos to concert halls, who now cater to pianists who may use either.. it could also see more concerts with more young people who 'stick with piano' instead of 'rage quitting' because they can't envisage becoming good pianists, not least because current key sizes.

At the same time... with modern engineering as it can be, I imagine ways of 'snapping in' different keyboards to a piano body. Difficult because of different distances from strings to keys (all kinds of leverage differentials or other dramas) - but what's possible can be just too expensive for eventual use cases I suppose. That kind of may be one such cul de sac at least for concert halls.

But dpianos... why not - all sizes - different expressions available via all kinds of sensors.. choosing between 'grand piano' mode and 'Roly Seaboard' mode

I feel like I'd probably only want to replace my dpiano with something offering choice of size and choice of behaviours (respect all grand piano action input/output.. to full touch expression using aftertouch with sensors to play vibrato etc... and so on). Until that kind of thing, if it comes along, I'm happy with the keys I've got - but.. if I were new to music, I'd prefer if the whole music world already offered pianists at least 2 main default key sizes. Manufactures of dpianos have 'the sky' as their limit.. rather than wanting a strange thing, I'd love a piano-like thing which can do what the Seaboard can too. Why not? Smaller keys would be extra cool too, if it was a snap in thing.. pull out the big ones, put in the small ones. I'd want both - I felt there were advantages to me as a musician, to putting up with piano sized keys.

The smaller key factor used by a lot of synths in the past did not prepare me for piano in my later times. After being very comfortable with smaller keys for so long, getting into real pianos and good dpianos for piano software, it was a stretch (pun) and quite a jump - BUT - I did feel that my musicianship improved a lot.. because of the struggle with larger keys.. in a way it's everyone's same struggle.. and I do think my playing would have remained 'lesser' if I didn't say "You know what, I'm going to get a piano" (which turned into getting Pianoteq).

Leaves me wondering, if smaller keys would be good, overall in 'the whole human population' really - or not. Would it mean, more can play the classics, or would it amount to more 'throw away' performances, in any genre/mode?

Would it lead to better compositions (esp. classical world), or would we lose a kind of extraordinary take which comes from the kind of Chopins of the world who make extraordinary leaps (from bare physicality through to that sparking deeper expressions of a musical nature.. difficult for even the best pianists in any generation). How can we make that possible, by making the ultimate classical music tool.. easier to play??

Would it lead to worse compositions, or would we gain a kind of extraordinary leap which comes from something like 'there are now more Chopins everywhere'

When I jump on an old synth.. I can't imagine being able to play my later compositions with the same 'feeling' - but maybe that would come with time on the smaller keys?

Those things are always fascinating to imagine.. but reality bubbles along just fine for most.. but in general a choice of piano key size would be likely a huge advance in music, when I imagine it happening.

Cool thread weightedKeys!