Bitcoin blockchain is growing big, yet its transaction capacity hit its limits in 2017. One solution heavily discussed within the bitcoin community is to let it grow faster by increasing size of the blocks. However, making transactions smaller instead of blocks bigger is more sustainable and also brings other additional benefits. In this paper, we focus on space wasted by non-cryptographic use of hashes and uncompressed numbers within transaction inputs. In our analyses, we show that transactions can be made approximately 16% smaller, depending on their complexity.