I suck at summarizing in the title; but I read that for shinkansen, (or some, at least) if you measure and add all three dimensions of your suitcase, it should be under 161 cm. Otherwise you need to reserve a seat with oversized storage.
While watching a video on the topic, it showed a spot where you can place your bag to see if it fits within the dimensions. ( in case you want to see: https://i.imgur.com/8r4PYLA.png ) It measures 50 by 30 by 80 cm.
My suitcase is over on one of the dimensions (the depth) measuring 33 cm whereas it's 30 on the display used at the station. But the dimensions added is still 157 – 158 cm total. Is that fine? Or do all dimensions need to fit within the limit?
by MintMochaMayhem