The Osmotic Pressure Calculator computes the osmotic pressure of a solution using the van’t Hoff equation, Π=i C R T\Pi = i \, C \, R \, TΠ=iCRT, where Π\PiΠ is the osmotic pressure, iii is the van’t Hoff factor, CCC is the molar concentration, RRR is the gas constant, and TTT is the absolute temperature in Kelvin. By entering these values, the calculator determines the osmotic pressure in atm and shows the substitution formula. This tool is useful for chemistry students and researchers studying colligative properties, solutions, and osmotic phenomena in chemistry and biology.