This paper presents how to select tuning factor and quality factor in designing of a single-tuned passive harmonic filter. Tuning factor and quality factor must be considered before a decision of filter parameters(R, L and C). In literature, the study about these two factors has not been performed and only empirical values have been used in the passive harmonic filter design so far. As an empirical value, in cases of 5th and 7th filter, tuning order has been used $4.8^{th}$ and $6.8^{th}$ respectively and quality factor has been used in a range of 30 and 60; therefore, we will propose how to decide these two factors in this paper. If a single-tuned passive harmonic filter were offtuned, its performance would be deteriorated substantially and resulted in a parallel resonance between grid inductance and filter capacitance. In order to avoid this side effect from off-tuning, the filter must be tuned on some preceded order not on the exact order. In other words, total filter impedance must have reactive impedance on a tuned frequency. In this paper, tuning factor is derived by using a bode-plot based method and then performance of filter is confirmed as a harmonic current absorption rate which harmonic source flows through filter; and quality factor is also derived by using the same method and then the performance is confirmed by the same filter current absorption rate. Finally, the performance of proposed passive harmonic filter design using the tuning factor and quality factor is verified by experiment. Experimental results show that the $5^{th}$, $7^{th}$, $11^{th}$ and $13^{th}$ current harmonic distortions meet IEEE-519 requirement.