[darkwater]

  echo <input id=kmbefore><input id=kmafter onleave='alert( (kmafter.value - kmbefore.value) * priceperlitterperkm )'>

 > index.html to make it available to anyone, Worldwide, for free!

You are conveniently leaving out that you already must have:

* a server running 24/7 on the internet, paid for each month

* purchased, setup and keep paying every year a domain name

* configured a web server in that server, ideally with automated SSL certificate issue and renewal

[e12e]

That, or know that https://neocities.org/ exists.

[utopiah]

Well yes I'm indeed assuming that you have :

- a place with electricity

- an Internet connection

- a computer, no matter how small (it can literally be a-cig)

which isn't true for literally every one but clearly for OP was.

You don't need a server in the cloud though, like I said a home server is enough.

[echoangle]

Or just use GitHub pages.