Table 1. Sample size calculation with double population proportion formula using Epi-info version 7 for the unmet need of modern FP in South Gondar, Ethiopia, 2017 [7, 9, 15].

Factors	%outcome exposed	Power	% outcome unexposed	OR	10%	Design effect	Sample size
Partner disapproval	11	80%	41	2.63	32	1.5	528
Have you ever used FP? No	43.7		56.3	2.29	23		379
Number of living children(3/4)	32.2		67.8	2.84	20		324