There is no unified/clear sizing! You are at risk of waisting money and NO returns! The shirt I received is completely unusable for me, as it doesn't fit, instead of agreeing to return, Posh is asking me to resell it on their platform, and I'm not in the business of selling items! Their ruling on this matter has cost me $266.57, which could have been mitigated if the shirt had been returned and resold alongside the seller's other items. This would have been avoided with a proper platform of unified measurement standard as part of the metadata for listings accompanied by a link to a measurements guide/definition.