I specifically needed a numpad on my keyboard so I went for a 40% ortholinear. I have the numpad on a layer on the right hand side. With all keys reachable from the home row, I can use it more easily/quickly than on a full-sized keyboard so it's really the best possible solution.

I've configured the layer button so that it can either be held down for quick use, or toggled with a double tap.

The thing about keyboards is that nowadays there's something for almost everyone. You don't have to do what others say, but you might try it, and it might work for you too. If it doesn't - that's fine, you will find something else. There's an absolute abundance of models in the most popular layouts - 60%, 65%, 75%, TKL, 1800, 100%, and there's more and more choice for the more niche sizes like 40%. And on the custom market there are even more things - like you want your numpad, but don't care about the F row? There's f-row-less 1800. You want your dedicated F keys but want to save horizontal space? There's 60% with an F row added.

For something new that you aren't used to, IMO it's a good idea to try it in a "reversible" manner - i.e. trying to stick with F keys on a layer on a board that still has dedicated F keys. For me this was arrow keys - I was previously on a 75% keyboard and I wanted to try home row navigation; I still had dedicated arrow keys, but I forced myself into using IJKL on a layer that I activate with my left pinkie - and ended up liking it (it's still what I'm using to this day). I agree with what others said about ortholinear - it's a bit better for placing a numpad on a layer; I personally have it so that 456 line up with JKL - this requires the minimum amount of hand movement and it works pretty well - maybe not as well as a dedicated numpad block because it's not physically separated - but I'd say it's 90% there.

You could always get a separate numpad you move to the right of your keyboard when needed, and move out of the way when it's not

Look up Miryoku. I use 36-key keyboards, and I have a numpad, never have to move my fingers very far for any key, including symbols, and find it very comfortable for my arthritic hands.

When I bought my cheapo "Baby's first mechanical keyboard" the one with the numpad was more than I wanted to spend so I said "Fuck it, I'll get used to TKL".
So I did. To a point that now even on keyboards with the numpad I still use the top row out of habit. You can imagine the look on my coworkers faces.

TL;DR: Just force yourself to I guess lol

I use a CRKBD and have a layer where I have a numpad.

I used to be that way, but the extra mouse space is undeniably better for me, so I just learned to top-row number. I still very much miss my numpad, though, and I do want to get a separate numpad one day.

I got a good keyboard at a good price, so I just kinda sunk cost fallacy-ed myself into accepting it. I didn’t use the numpad too often though.

I use a blank 75% keyboard.

For the numbers, I use F and J as points of reference to find whatever number I need. This is enough for a majority of cases, and I haven't been using a numpad for most things in the first place.

4 and 5 above F, 6 and 7 above J, 0 is 3rd from the right, 1 and 2 are two leftmost. The rest are handled by the process of elimination.

But when I need to fill out spreadsheets worth of data, I just use a Bluetooth numpad that also doubles as a calculator. For that purpose, it's just too convenient. And no, QMK layers didn't help in my case. It would help if I used ortholinear keyboard, however.

Tkl is the smallest I'll go

I'll take this question to be about getting used to it after programming a suitable layout. I daily drive a keyboard with 42 keys.

How to get used to it? Patience and acceptance. You need to be patient. It won't be a quick process. And you need to accept that you will be slower for a long time. And accept that the coming period will be frustrating. You need to tell yourself this explicitly: I will learn this layout and it will be painful but I accept that this is the case.

A practical tip: do not go back to a comfy keyboard when frustrated. If you go back to your normal keyboard again and again, your muscle memory will not update as well (in my experience). Every time you go back you kinda undo some of the muscle memory updates (not science just my experience). Once you body gets that this is how it is now, it will adapt to this new normal and you will learn the layout.

Once I learned a non qwerty keyboard layout. That was one of the most frustrating things I have ever done (much harder than getting used to layers on a 40%). I got through it by accepting the frustration: you feel it, note to yourself in your head that this is indeed what you are feeling, breathe, accept it and continue using the layout. Slowly if needed! As long as you keep using it. You can only get good with it if you stick with it. I'm not saying that you need to go this route. But if you want to, you gotta get a bit zen with it.

@bridgeenjoyer
I've spent years with a lovely huge IBM Model M.

Then I've moved to a TKL (no numpad) keyboard: no pain at all, except (sometimes) when in need for Windows Alt-numpad sequences for special characters.

Then I've moved to a 68 keys split keyboard! And I love it, since I (almost perfectly) customised it for my needs.

And I'm now thinking to go to a 42-keys split keyboard... (see Piantor Pro)

Some keebs have a function key you can hold that makes part of the right hand keys be a number pad layout.

I have a 60% that I've used enough to confidently say I won't get used to it, but just not having the numpad I got used to easily. You can also have a separate numpad detached from the keeb if you want it out of the way but still need it from time to time.

Depends on your needs. If you actually use the mumpad a lot because you are an accountant or just do a lot of data entry, yeah, keep the mumpad. If you're not actually using it much, then it's really not that big a deal. You can also get a separate numpad and use that for the times you do need it, then move it out of the way the rest of the time.

For my work setup, I use a full layout with numpad. I have too much data entry, top num row would only slow me down and give me hand cramps from stretching to the furthest keys so much.

Personal computer setup, I don't have a num pad. I need to type numbers rarely and don't miss it.

If you can't go 5 min without missing your numpad... why get rid of it?

nothing saying you can’t get a separate numpad and place it on the opposite side of your board from your mouse

I use a 60% with a macropod, the macropod is purely for numpad stuff in Blender and some window management shortcuts. Otherwise I use WASD for arrow keys with a modifier and a bunch of custom QMK stuff. Could always set a layer shortcut to turn a section of keys into the numpad on a smaller keeb. The only issue is when you use a keyboard without your config and can’t function!

I need my numpad. That was the worst choice for me given my work and workflow at home. I could do without the number row across the top. I guess I haven't really given a great deal of thought to my most maximally effective keyboard layout.

Context: I bought an 80% out of frustration with another logitech keyboard dying an early death with the double strike key issue.

I went a full school year with a 12" laptop. The answer for me was: you don't.

Without a numpad? That took almost no time at all. I use laptops all the time without numpads so not much changed. It's only going smaller than TKL that I've had any problems.

I’ve just been used to it due to laptop form factors, but I did eventually break down and get a separate number pad for intensive stuff (spreadsheets, taxes, etc) when needed. Not the most elegant solution but it means that I get to keep the small keyboard 95% of the time.

I am not "used to" my smaller keyboard. I never used the numpad in the first place. Most of the time I don't enter numbers anyway.

You may not need a smaller keyboard after all?

QMK layers!

I focused on finding a keyboard that would suit me physically; (crkbd, also had the bonus of seeming like an easy first keyboard to build)

After building it, I started experimenting with the configuration and see what QMK features could make it work for me

• I didn't consider 4-row keyboards: I never use the number row, so building a larger keyboard would just be a waste
• Basically I created my layers so that mainly the left hand selects the layer, and the right uses the keys comfortably
• Holding down two keys (left thumb+index) selects my "mode" for the right half:
  • Numpad on layer 2
  • F keys in a numpad layout on layer 3
  • Special symbols on layer 4
  • Multimedia/volume keys
  • etc etc
• I even made a sticky layer for gaming: press a combination once, and e.g. layer 8 stays selected, with WASD keys etc for the left split. Pressing a thumb key temporarily selects layer 9, which transforms the left split to a layout of numpad keys for weapon selection, Esc, etc

Sorry if it sounds complicated, it's a bit difficult to describe 😅 But the point is that I configured the layers, so they are configured in a way that suits me, and it's easier to remember and use than it seems: after a week or so I was fully used to it! It's been a few years and I haven't configured it much since then.

Just don't be shy to check the QMK documentation and think creatively to see what kind of keys you would want to set to make a small keyboard more comfortable for your usage!

Edit: I found the configuration file so I took a screenshot! Layers 8 and 9 are the "gaming" layers (also, ignore the letters: since I was learning a new keyboard anyway, I took the opportunity and switched to colemak as well 😅)

BTW I used the "numrow" keys for the numbers instead of their numpad versions: this way I don't have to worry about the numlock 😅

Numpad will be þe happiest discovery you'll make, and you'll never want to go back. Oþer keys, maybe not so much. Squeezing down can result in endless tweaking to get a setup where þe lag doesn't drive you insane, but you are also not accidentally triggering wrong keys.

If you want to try it first, install and configure kanata. It does þe same þing as QMK, in software (vs firmware). You can set up your keyboard layout wiþ N keys and try layers and see how it feels. I recommend starting small - e.g., put a layer switch on a key under your left hand, and map þe layer to a 10-key numpad under your right. Use þat for a while and you'll never want to go back.

After you get used to þe concept of layers, try adding anoþer layer wiþ symbols. You'll see pretty quickly how people can get down to 30 (or fewer!) keys. For me, þat's too much chording - I'm using a 42-key board, and it's about as small as I want to go.

Þe only þing you won't experience wiþ kanata is þumb keys. Most small keyboard put multiple keys under your þumbs, whereas you'll only ever have a space bar on a typical keyboard, and þat'll spoil it a little. Still, kanata is awesome software, and even if you never get a smaller board, you'll probably end up loving kanata.