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Shelf Spacing

Enter the total length and shelf count to get even spacing instantly

Accounts for shelf thickness too, so every compartment ends up exactly the same size.

cm
cm
Compartment gap (clear space) –
Compartments –

Shelf-by-shelf positions (from the bottom)

    Real lumber can have slight thickness variance, so it's a good idea to double-check with an actual measurement before cutting.

    What is a shelf spacing calculator?

    The Shelf Spacing Calculator works out the exact even-spaced position of every shelf in a bookcase or cabinet from just three numbers: the total internal length, how many shelves you want, and the shelf thickness. It divides the remaining space — after subtracting the room the shelves themselves take up — evenly across every compartment (shelf count + 1), so you don't end up with uneven gaps from eyeballing the layout. The result comes with both an exact position list measured from the bottom of the case and a diagram drawn to match your actual proportions.

    How to use it

    Enter the total internal length of your bookcase or cabinet, how many shelves you want, and the shelf thickness. The compartment gap and compartment count are calculated instantly, and a list below shows the exact install position of every shelf measured from the bottom. The diagram is drawn to match your actual input proportions, so you can preview roughly what the finished piece will look like.

    When it comes in handy

    Frequently Asked Questions

    Does "number of shelves" mean the shelf boards themselves, or the compartments?
    It's the number of shelf boards. For example, adding 4 shelves creates 5 compartments total (above and below each shelf), and this tool makes sure all 5 compartments end up evenly spaced.
    Why do I need to enter the shelf thickness?
    Because the shelves themselves take up space. Without subtracting shelf thickness, the actual gap once installed would end up smaller than the calculated value.
    What are the calculated positions measured from?
    The very bottom of the case (bookcase or cabinet) is treated as position 0, and each shelf's position is the distance from there to the bottom face of that shelf.