For the chi-square test, the effect size index w is calculated by dividing the chi-square value by the number of scores and taking the square root, and it is considered small if w = 0.10, medium if w = 0.30, and large if w = 0.50.

There are three ways to measure effect size: Phi (φ), Cramer’s V (V), and odds ratio (OR).

https://www.statology.org/effect-size-chi-square/

As Jos Feys rightly says, the reader can see the link below. It calculates the effect sizes in different studies online and very simply for you.

https://www.statskingdom.com/effect-size-calculator.html