The radix-2(k) fast Fourier transform (FFT) algorithm is used to achieve at the same time both a radix-2 butterfly and a reduced number of twiddle factor multiplication. In this paper we present a new identical radix-2(k) FFT algorithms, which has same number of butterfly and twiddle factor multiplication. The difference is only in twiddle factor stage location in signal flow graph (SFG). Further, analyze these algorithms and is shown that the round-off noise of identical radix-2(2), radix-2(3), and radix-2(4) FFT algorithms at output is reduced 27%, 8%, 3% respectively.