The need to use non-destructive methods for studying the strength of brick structures is an urgent task today. One of the non-destructive methods is the use of formulas for calculating the compressive strength of brickwork.This article is about a comparative analysis of three empirical formulas for determining the strength of brickwork for compression, used in building codes of Russia and Europe. The graphs below show the dependence of the design values of the ultimate strength of brickwork under compression on the strength of the brick. This makes possible to see the difference in the calculation methods. Moreover, there was a discrepancy found in professor Onyshika's formula during the work from his "Stone-made constructions" monography with formula in Stone-made and armo-stone made constructions guideline. (SNiP II-22-81).