Blocks

This article lists the hitboxes (aka bounding boxes) of all blocks in 1.8.

Blocks are ordered by length, then width, then height.

Images were taken with Blockbench, or from the Minecraft wiki.

Simple Blocks

Block	Widths (b)	Height (b)	Comments	Image
Wall (4-sided)	1 × 1	1.5
Default	1 × 1	1
Soulsand	1 × 1	0.875	Looks like a full block, but is actually 2 px lower.
End Portal Frame	1 × 1	0.8125
Enchantment Table	1 × 1	0.75
Bed block	1 × 1	0.5625	The bottom doesn't look tangible, but it actually is.
Slab	1 × 1	0.5	Inversible.
Daylight Sensor	1 × 1	0.375
Trapdoor (horizontal)	1 × 1	0.1875	Can be flipped to its vertical variant.
Repeater	1 × 1	0.125
Carpet	1 × 1	0.0625
Lily Pad	1 × 1	0.015625	Is ¼ of a pixel in height.
Snow Layer	1 × 1	0 0.125 0.25 0.375 0.5 0.625 0.75 0.875	Snow layers look 2 pixels higher than their real height. Despite having no height, a single layer of snow is tangible.	... (gif)
Anvil	1 × 0.875	1	Centered. Orientable (2 variants). Looks thinner than it actually is.
Piston Base (Powered)	1 × 0.75	1	Orientable (4 variants).
Wall (3-sided)	1 × 0.75	1.5	Orientable (4 variants)
Wall (2-opposite)	1 × 0.375	1.5	Centered. Orientable (2 variants). Placing a block on top of it doesn't change its hitbox, despite its appearance being different.
Fence (2-opposite)	1 × 0.25	1.5	Centered. Orientable (2 variants)
Fencegate	1 × 0.25	1.5	Centered. Orientable (2 variants). Can be flipped to a variant with no hitbox.
Trapdoor (vertical)	1 × 0.1875	1	Orientable (4 variants). Can be flipped to its horizontal variant.
Door	1 × 0.1875	1	Orientable (4 variants). Can be flipped to another variant.
Ladder	1 × 0.125	1	Orientable (4 variants).
Pane (2-opposite)	1 × 0.125	1	Centered. Orientable (2 variants)
Chest (long)	0.9375 × 0.875	0.875	Must be next to another chest.	...
Dragon Egg	0.875 × 0.875	1	Centered. Looks drastically different than its hitbox.
Cactus	0.875 × 0.875	0.9375	Centered. Hurts entities close to it.
Chest	0.875 × 0.875	0.875	Centered.	...
Cake	0.875 × 0.875 0.875 × 0.75 0.875 × 0.625 0.875 × 0.5 0.875 × 0.375 0.875 × 0.25 0.875 × 0.125	0.5	The full cake is centered. Each bite takes away 0.125b from the West (-X)	... (gif)
Wall (2-adjacent)	0.75 × 0.75	1.5	Orientable (4 variants).
Wall (1-sided)	0.75 × 0.5	1.5	Orientable (4 variants).
Fence (1-sided)	0.625 × 0.25	1.5	Orientable (4 variants)
Wall (default)	0.5 × 0.5	1.5	Centered.
Head (default)	0.5 × 0.5	0.5	Centered.	...
Head (walled)	0.5 × 0.5	Start: 0.25 Top: 0.75	Orientable (4 variants).	...
Pane (1-sided)	0.5 × 0.125	1	Orientable (4 variants). Appears 1 pixel longer than it really is.
Flowerpot	0.375 × 0.375	0.375	Centered.
Fence (default)	0.25 × 0.25	1.5	Centered.

Composite Blocks

"Except" represents an intangible zone rather than a tangible one.

Block	Widths (b)	Height (b)	Comments	Image
Stair (normal)	Base: 1 × 1 Top: 1 × 0.5	Base: 0.5 Top: 1	Orientable (4 variants). Inversible.
Stair (outer)	Base: 1 × 1 Top: 0.5 × 0.5	Base: 0.5 Top: 1	Orientable (4 variants). Inversible.
Stair (inner)	Base: 1 × 1 Except: -0.5 × -0.5	Base: 1 Except: -0.5	Orientable (4 variants). Inversible.
End Portal Frame (eye)	Base: 1 × 1 Eye: 0.375 × 0.375	Base: 0.8125 Eye: 1	The eye looks bigger than it is. (Appears 8 px in width, but is actually 6 px wide)
Cauldron	Base: 1 × 1 Except: -0.75 × -0.75	Base: 1 Except: -0.6875	The bottom doesn't look tangible, but it actually is.
Brewing Stand	Base: 1 × 1 Rod: 0.125 × 0.125	Base: 0.125 Rod: 0.875	The base looks smaller than it really is.
...

Other

Block	Widths (b)	Height (b)	Comments	Image
Boat	1.5 x 1.5	0.6	Entity.