The invention generally relates to methods for determining aneuploidy of cells with respect to a control sample. In certain embodiments, the method involves exposing a sample to a plurality of probes capable of capturing DNA from at least one chromosome suspected of having an altered copy number, and at least one control DNA sample known or suspected to have a stable copy number, capturing and sequencing DNA that binds to the probes, calculating a chromosomal read fraction; determining a sample specific scaling factor; scaling the chromosomal read fractions, normalizing the scaled read fractions, and determining a copy number state of at least one chromosome.