Q value, Q factor, and Q score may refer to:Q factor, a measurement of a resonant system's relative bandwidth Radiation weighting factors used in ionizing radiation dosimetry Q factor (bicycles), the width between where a bicycle's pedals attach to the cranks q-value (statistics), the minimum false discovery rate at which the test may be called significant Q value, a difference of energies of parent and daughter nuclides Q Score, in marketing, a way to measure the familiarity of an item Fusion energy gain factor Q, the ratio of fusion power produced in a reactor to the power required to maintain the plasma in steady state Q, in number theory, a way of representing decimal numbers in a fixed-point math system Q factor, a way of representing bit error rates in dB