This String Gauge calculator is handy.
https://tension.stringjoy.com/

This is a cool tool. We need to have them add the Chapman Stick catalog of instruments...!

I've noticed that you can use a heavier wirewound string, (.018w)
instead of a plain string to get almost the same tension. (.016p)
It might be worth testing out each one, to see the difference in tone.

When I received my Newtone strings from the UK for #404, there was one wirewound string that had a tone that really annoyed me. Someone on this forum suggested replacing it with a plain string and it did the trick. I now have a perfect set of strings for the tones that I prefer.

I've done the same sort of thing with every stringed instrument that I've owned. I often make up a set of custom strings based off of whatever works, until I find the tones that I'm happy with. After making a set of strings for my PRS Custom 24 guitar, I discovered that Ernie Ball had an identical set of strings called the 'Hybrid Slinky'.

I follow a simple rule of thought. Whatever makes you Happy!

Here is the Kalium calculator which is more suited to tap guitars as you can choose 'Bass', add as many strings as you want, and there is no limit to which strings you can specify as Kalium have .008 to .266 available for bass scale lengths.
Obviously this will be a little approximate for other brands of roundwound, but still useful.
https://stringtensioncalculator.com/

Here is a 10 string Stick with a classic light set:

WerkSpace,

Interesting that you preferred the tone of a thick plain to an equivalent roundwound. Thick plains are very stiff, which seems not ideal for response to tapping. Personally i find they have an unpleasantly inharmonic tone due to the stiffness.
I design custom single string sets for all my guitars/basses/tapguitars, and i make an effort to minimise the gauge of the largest plain and use a thin roundwound next to it. Often i will let the optimum plain-to-wound transition dictate the transposition of the entire tuning.

I used a thinner plain string, instead of the thicker wirewound.
The tension was almost identical, but had a better tone.

To clarify, i understand that for the same tension, a plain steel can be roughly .002 thinner than a roundwound, due to the air gaps in the roundwound lowering the mass.
By 'a thick plain' i mean a plain steel over .016, i did not mean it is thicker than the roundwound it replaced.
If you swap out a thin roundwound for a plain steel, keeping the same tension, it is inevitable that you have to use a 'thick plain' of over .016.
I find plain steels over .016 start to become unpleasantly stiff and inharmonic, even on a bass scale.

I have found that a step-down in tension from wound to plain helps to balance the volumes and tones. It lowers the high volume of, and mellows the harsh tone of, the plain. So if you replace a wound with a plain i suggest reducing the tension, this also helps in another way by reducing the gauge.

I checked the string gauges on my Newtones.
https://newtonestrings.com/about-newtone-strings/
On the bass side, it was the .018 wirewound that I didn't like.
It was replaced with a smaller gauge plain to achieve a better tone.

Ahh ok that does make sense, i did not expect a wound as small as .018 (which would have a tiny core like .008), i can imagine a .016p being just as good or better.

Hi. This is an old topic but may I check on my understanding?

Since you have such an early Stick, I think you're effectively saying that the Newtone 10 string set is an equivalent to 'light gauge classic'?

Also, that you've tweaked your set to use a .016p in place of the .018w that is standard in the Newtone 10 string set?

Do I have that correct?

My experience with this is a little different. For a bass string a .016 might be okay, because of its vibrating length, but it lacks the suppleness to be a good melody string. You'll get way too much inharmonicity as you get closer to the bridge. If you don't want to use an .018, then a .015 would be the minimum, but a .014 would be better..

relying on sources of information for guitar strings in this case ignores the different technique we are using. Tapped strings behave differently, and many of the "rules" people have come to accept for guitar and bass strings no longer apply.

Just my experience and Emmett's R&D...