Advanced options
Books are HEAVY: ~20kg per full metre, so a 3m unit carries a small adult: fix tall cases to the wall (toddlers climb) and check shelf spans (past 80cm, boards sag under books: the same rule as alcove shelving). Standard paperbacks want 20cm of shelf height, hardbacks 24-28cm, art books and vinyl 33cm+: mixed-height shelving wastes less air.
What The Bookshelf Capacity Calculator Works Out
- Capacity: shelf metres x books per metre. Standard paperbacks at 2.5cm a spine shelve 40 to the metre, hardbacks at 4cm about 25, and a domestic mix lands near 33, so the common three-metre arrangement holds about 100 books.
- Weight when full: about 20kg per loaded metre, so a full 3m unit weighs as much as a small adult. Strap tall cases to the wall against climbing toddlers and furniture-tip statistics.
- Reading it all: the capacity divided by 20 books a year and by a book a month, the British average. Every serious collection outruns its owner's remaining velocity, which the tsundoku tradition treats as a feature: the unread shelf is a menu of future selves, not a backlog of failure.
- Books you own (advanced): turns the question round: how many metres your collection needs at your mix, and whether the shelving you have leaves spaces or an overflow for horizontal stacks on top.
- Books you read a year (advanced): your own pace instead of the averages, giving the years to read the full shelf and your whole collection.
- Weight per metre (advanced): 15kg for paperbacks, 20kg for a mix, 25kg or more for hardbacks and art books. Serious collections live on the ground floor for structural prudence as much as habit.
- Shelf width and spacing (advanced): how many shelves your total length makes and how tall a single column would be. Paperbacks need 20cm of clearance, hardbacks 24-28cm, art books, atlases and vinyl 33cm plus; an adjustable case tuned to the real collection stores about a quarter more than factory spacing.
- Load per shelf (advanced): the kilos each shelf carries. Past an 80cm span, 18mm boards bow under books, the same rule as alcove shelving, so widen the board, add a centre support or shorten the shelf.
- Double-stacked (advanced): a second row behind the first doubles the capacity and the weight at the price of forgetting the back row exists. Horizontal stacks on top of vertical runs are the honest overflow valve.