Ratio scale is a type of measurement scale that possesses all the properties of an interval scale, along with a true zero point. In ratio scales, the measured values not only indicate the order and relative differences between variables but also allow for the absolute comparison of magnitudes. This scale has a clear and meaningful zero point that represents the absence or total lack of the measured attribute.

Ratio scales provide the most informative level of measurement as they enable researchers to perform a wide range of mathematical operations. In addition to supporting all operations allowed by interval scales (e.g., addition, subtraction, multiplication, division), ratio scales allow for meaningful applications of ratios, proportions, and absolute differences.