Handy RF/circuit calculators

Coplanar waveguide impedance calculator:

https://chemandy.com/calculators/coplanar-waveguide-with-ground-calculator.htm

https://www.microwaves101.com/calculators/864-coplanar-waveguide-calculator

advanced version:

http://wcalc.sourceforge.net/cgi-bin/coplanar.cgi

Microstrip waveguide impedance calculator

https://www.pasternack.com/t-calculator-microstrip.aspx

https://www.eeweb.com/tools/microstrip/

Parallel plate capacitance calculator

https://www.calctool.org/CALC/eng/electronics/parallel_plate

Wire Inductance calculator

https://www.eeweb.com/tools/wire-self-inductance-calculator/