Guinness World Records mentions, 'The Plank Length'. The smallest possible size for anything in the universe is the Planck length, which is 1.6 x10⁻³⁵ m.
I have compared the equation Rₘᵢₙ = (G/c²)·m to the Planck length.
When Rₘᵢₙ = (G/c²)·m = Lᴘ (plank length). And the finding is:
Mass (m) will be approximately 21.77 micrograms, which means that for masses greater than this, R(min) will be greater than the Planck length. And for masses smaller than this, R(min) would theoretically be smaller than the Planck length, but physical explanations on such small scales are not well defined by our current understanding of physics.
The Planck length contains the smallest meaningful length scale because it represents a fundamental limit below which the classical concepts of space and time will not apply, marking a boundary of our current physical theories.