We suspect that almost every investigator studying complex genetic traits has faced some variant of this quandary whether it is due to limitations of time, hardware, software, willingness, or ability to run all the simulations one would need to calculate power for all of one’s scenarios of interest. More formally, we can generalize this quandary to the following question. Given known or at least precisely estimated power for a given effect size, design, sample size, and α level, can we quickly and easily compute sufficiently accurate power estimates for the same design and effects size, but for different sample sizes and/or α levels, and if so, how? Our aim in this paper is to address this question and after a careful empirical analysis we believe that the answer is unequivocally, “Yes.”
