A method for empirical estimation of Planck's length, mass, and time is proposed, which is based on the characteristics of the electron, Avogadro, and Euler numbers, and the fine structure constant. Basic physical constants can be expressed in terms of Planck's length, mass, and time. The disadvantage of this method is that Planck's elementary particle does not exist in nature. Planck's particle is presented in a hypothetical, virtual form, its characteristics are theoretically calculated through the reduced Planck's constant, Newton's gravitation constant, and the constant speed of light in a vacuum, and the accuracy of these characteristics is low. This is due to the low accuracy of the Newtonian constant of gravity. This shortcoming can be eliminated if the characteristics of the hypothetical Planck particle are associated with a real elementary particle, for example, with an electron, and through its characteristics with the characteristics of leptons and baryons. Since the characteristics of leptons and baryons are determined experimentally and are among the most accurate, for example, for a proton now is 11 decimal places, establishing a connection with them of a hypothetical Planck particle will increase the accuracy of the values: of Planck's length, mass and time, of Planck constant, of elementary electric charge, of the Newtonian gravitational constant, of electron mass, of Planck temperature up to the accuracy level of a proton. As is known, the 26th General Conference on Weights and Measures decided to define one of the basic SI units of measurement through physical constants. In particular, with this solution, the kilogram is now defined in terms of Planck's constant, and the ampere is now determined in terms of the value of the elementary electric charge. Accordingly, with increasing accuracy of the values of Planck's constant and elementary electric charge, the accuracy of the values of a kilogram and Ampere will increase.