My project number 25 from 2010 about transmission lines was originally in Excel format.
Now in 2021 I have done here the same with html and Java scripts, which i hope is easier to use.

Coaxial cable

Zo / Ω = 138 * log(D/d) / SQRT(ε)

Give inner diameter D of the outer conductor. D and d in same units.

❶.

Give outer diameter d of the inner conductor

❷.

Give dielectric constant ε of the media between conductors, for air it is 1.

❸.

Cable impedance is:

Cable capacitance [far end open] is: ; C / pF/m = 24.1 * ε / log(D/d)

Cable inductance [far end shorted] is: ; L / μH/m = 0.459 * log(D/d)

Capacitance and inductance valid only, when cable length is much less than a wavelength.

Velicity factor v is: ; v = 1 / SQRT(ε)

Parallel line cable

Zo / Ω = 120 * ACOSH(S/d)

Give wire distance S. S and d in same units.

❶.

Give wire diameter d

❷.

Cable impedance is:

Parallel strip-line

Zo / Ω = 377 * a / b , where a much smaller than b.

Give strip distance a. a and b in same units.

❶.

Give strip width b

❷.

Cable impedance is:

Strip above ground plane

Zo / Ω = 188.4 * a / b , where A much smaller than B.