Abstract: In this piece we attempt to compare and evaluate the differences in the blockchain size and data storage requirements, for Bitcoin and Ethereum. Surprisingly Bitcoin’s blockchain is still larger than Ethereum, however this is about to change and Ethereum is soon set to surpass Bitcoin with its rapid appreciation in blockchain size. On the other hand, this metric is not a particularly useful comparison, as to learn useful information about the Ethereum network one needs to perform significantly more computations and generate far more data.