I use Mini Ring Core Calculator. It calculates length of wire and maximum wire size in AWG or mm units (your choice), for most Amidon cores, both iron and ferrite. It also lets you enter the number of turns and shows you the inductance and reactance for a given number of turns on a given core at a given frequency, so you can see what happens if you add or remove a turn. It will also calculate air core coils. Also has a resonance calculator for LC values, and can tell you inductance of a straight piece of wire. I use version 1.2, but see there is a newer version, now.
Free, from here:
Very handy for me. -- Donald, KB5PWL
On 2/10/2019 1:46 PM, Evan Hand wrote:
There is a web page that calculates inductance AND wire length needed with 1" leads. It is here: