The absorption spectra of various sizes of nanoparticles of copper (Cu), silver (Ag), and gold (Au) are theoretically investigated. The Density Functional Theory (DFT), Time Dependent DFT (TDDFT), and Real Time TDDFT (RT‐TDDFT) are used to demonstrate how size and shape affect their optical properties and how these are evolved as the number of atoms increases. For this reason, the focus was turned on almost spherical NPs cut out from the corresponding crystal structure (called 0D), elongated ones (1D) and flattened ones (2D). The nature of the observed absorption peaks is further analyzed with the help of transition contribution maps (TCM) and induced density plots which help us identify the emergence of probable plasmonic resonances as the size of the nanoparticles increases.This article is protected by copyright. All rights reserved.