Shelf Spacing Calculator
Divide a height into evenly spaced shelves, allowing for the thickness of each shelf.
At a glance
- What you enter
- Total interior height, Number of shelves, Shelf thickness, Height of the item you want to store, Plinth or base below the bottom shelf
- What you get
- Clear opening between shelves, Clear opening in millimetres, Shelf 1 from the floor, Shelf 2 from the floor, Shelf 3 from the floor, Clear height at the top, Your item fits in one opening
- Formula shown
- Yes, every step, right below your results.
- Cost and privacy
- Free, no account needed, and nothing you type is stored.
See worked examples ↓ Read the FAQ ↓ Share this calculator ↓
Results are estimates for general information only, always verify with a professional or official source before acting on them.
How to use the Shelf Spacing Calculator
- 1 Enter Total interior height (in), The clear height the shelves have to fit inside.
- 2 Enter Number of shelves
- 3 Enter Shelf thickness (in), A nominal 1 inch board is 0.75 inches dressed. A nominal 2 inch board is 1.5 inches.
- 4 Enter Height of the item you want to store (in), Used to check whether the item fits in one of the openings. A hardback book is about 9.5 inches.
- 5 Enter Plinth or base below the bottom shelf (in), Leave at zero if the bottom shelf sits at the floor.
- 6 Press Calculate. You get Clear opening between shelves, Clear opening in millimetres, Shelf 1 from the floor, Shelf 2 from the floor, Shelf 3 from the floor, Clear height at the top, Your item fits in one opening, and every intermediate step stays visible under "How is this calculated?"
- 7 Change one number at a time to see what moves the result, that is usually the most useful thing a calculator can tell you.
Worked examples
Real numbers run through this calculator. Open any example to load it into the form above and change it.
Bookcase with six shelves
A 72 inch case, six shelves at 0.75 inches, with a hardback book to check.
You enter
- Total interior height
- 72 in
- Number of shelves
- 6
- Shelf thickness
- 0.75 in
- Height of the item you want to store
- 9.50 in
- Plinth or base below the bottom shelf
- 0 in
You get
- Clear opening between shelves
- 9.64 in
- Clear opening in millimetres
- 244.93 mm
- Shelf 1 from the floor
- 9.64 in
- Shelf 2 from the floor
- 20.04 in
- Shelf 3 from the floor
- 30.43 in
- Clear height at the top
- 0.00 in
- Your item fits in one opening
- 1
Seven gaps at 9.64 inches each.
Kitchen pantry with a plinth
An 84 inch pantry, five shelves at 0.75 inches, sitting on a 4 inch plinth.
You enter
- Total interior height
- 84 in
- Number of shelves
- 5
- Shelf thickness
- 0.75 in
- Height of the item you want to store
- 12 in
- Plinth or base below the bottom shelf
- 4 in
You get
- Clear opening between shelves
- 12.71 in
- Clear opening in millimetres
- 322.79 mm
- Shelf 1 from the floor
- 16.71 in
- Shelf 2 from the floor
- 30.17 in
- Shelf 3 from the floor
- 43.63 in
- Clear height at the top
- 0.00 in
- Your item fits in one opening
- 1
Six gaps at 12.7 inches each, so a 12 inch item fits.
Garage rack in 2x4 shelving
A 96 inch rack with four shelves of 1.5 inch stock.
You enter
- Total interior height
- 96 in
- Number of shelves
- 4
- Shelf thickness
- 1.50 in
- Height of the item you want to store
- 18 in
- Plinth or base below the bottom shelf
- 0 in
You get
- Clear opening between shelves
- 18.00 in
- Clear opening in millimetres
- 457.20 mm
- Shelf 1 from the floor
- 18.00 in
- Shelf 2 from the floor
- 37.50 in
- Shelf 3 from the floor
- 57.00 in
- Clear height at the top
- 0.00 in
- Your item fits in one opening
- 1
Five gaps at 18 inches each.
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Frequently asked questions
How do I space shelves evenly?
Should I use the nominal or actual shelf thickness?
How tall should a bookshelf opening be?
Does a shelf sag and do I need to allow for it?
Terms used here
Short, plain-language definitions of the words this calculator uses.