Energy cascade rates and Kolmogorov’s constant for non-helical steady magnetohydrodynamic turbulence have been calculated by solving the flux equations to the first order in perturbation. For zero cross helicity and space dimension $d = 3$, magnetic energy cascades from large length-scales to small length-scales (forward cascade). In addition, there are energy fluxes from large-scale magnetic field to small-scale velocity field, large-scale velocity field to small-scale magnetic field, and large-scale velocity field to large-scale magnetic field. Kolmogorov’s constant for magnetohydrodynamics is approximately equal to that for fluid turbulence $(\approx 1.6)$ for Alfvén ratio $0.5\leq r_{A}\leq \infty$. For higher space-dimensions, the energy fluxes are qualitatively similar, and Kolmogorov’s constant varies as $d^{1/3}$. For the normalized cross helicity $\sigma_{c}\to 1$, the cascade rates are proportional to $(1-\sigma_{c})/(1+\sigma_{c})$, and the Kolmogorov’s constants vary significantly with $\sigma_{c}$.