How Much Does a Cinder Block Weigh? Sizes & Weight Chart
How much does a cinder block weigh? A standard 8x8x16 concrete block weighs about 38 lb (28 lb lightweight). Full chart of concrete block sizes and weights.
By The Concrete Calculator Team ·
How Much Does a Cinder Block Weigh?
A standard 8x8x16 hollow concrete block weighs about 38 pounds (roughly 35 to 40 lb depending on the plant). A lightweight block of the same size weighs about 28 pounds. Smaller 4-inch blocks come in near 28 lb, and big 12-inch blocks run about 50 lb.
People say “cinder block” for any gray masonry block, but most blocks sold today are concrete masonry units (CMU) made with sand and gravel. True cinder blocks used coal cinders or fly ash, which made them lighter. The lightweight column in the chart below is the closest match to an old-style cinder block.
Concrete block sizes and weight chart
| Nominal size (W x H x L) | Actual size | Normal weight | Lightweight |
|---|---|---|---|
| 4 x 8 x 16 in | 3 5/8 x 7 5/8 x 15 5/8 in | ~28 lb | ~20 lb |
| 6 x 8 x 16 in | 5 5/8 x 7 5/8 x 15 5/8 in | ~35 lb | ~25 lb |
| 8 x 8 x 16 in | 7 5/8 x 7 5/8 x 15 5/8 in | ~38 lb | ~28 lb |
| 10 x 8 x 16 in | 9 5/8 x 7 5/8 x 15 5/8 in | ~45 lb | ~33 lb |
| 12 x 8 x 16 in | 11 5/8 x 7 5/8 x 15 5/8 in | ~50 lb | ~36 lb |
Weights are typical values for hollow units. Exact weights vary with the aggregate and the plant, so check the supplier’s spec sheet when weight matters, for example on a delivery truck or an upper floor.
Why the actual size is smaller than the name
Block sizes are “nominal.” The actual block is 3/8 inch smaller in each direction, so with a standard 3/8-inch mortar joint every block takes up exactly 8 x 16 inches of wall face. That is why the layout math works out in clean numbers.
Cinder block sizes: which one to use
- 4-inch block: veneer, partition walls, and capping.
- 6-inch block: interior non-load walls and short garden walls.
- 8-inch block: the standard choice for foundations, retaining walls, and garage walls.
- 10 and 12-inch block: taller retaining walls and heavy load-bearing walls, often grouted and reinforced.
How many blocks do I need?
Each 8 x 16 block covers 0.889 square feet of wall, so you need 1.125 blocks per square foot.
- Multiply wall length by wall height to get square feet.
- Multiply by 1.125.
- Add about 5% for cuts and breakage.
Example: a wall 20 ft long and 4 ft high is 80 sq ft. 80 x 1.125 = 90 blocks, plus 5% gives about 95 blocks. At 38 lb each, that is roughly 3,600 lb of block, so plan the delivery accordingly.
Our cinder block calculator does this for you, including mortar bags and fill for the cores.
How much does a pallet of cinder blocks weigh?
A pallet of 8x8x16 blocks usually holds 90 to 108 blocks depending on the supplier. At about 38 lb per block, that works out to roughly 3,400 to 4,100 lb, plus the pallet. That is too heavy for most pickup trucks, so arrange delivery.
Filling the cores
Hollow block walls are often grouted with concrete in reinforced cells. An 8-inch block has about 0.27 cubic feet of open core space when fully grouted, so a fully filled wall of 90 blocks needs roughly 24 cubic feet, close to 0.9 cubic yard. Use the concrete calculator or our cubic feet to cubic yards guide to convert.
FAQ
How much does an 8x8x16 cinder block weigh?
About 38 lb for a standard hollow block and about 28 lb for a lightweight block.
What is the weight of a 4-inch cinder block?
A 4x8x16 block weighs about 28 lb (normal weight) or about 20 lb (lightweight).
How many cinder blocks are in a square foot?
1.125 blocks per square foot of wall for standard 8x16 face blocks.
Is a cinder block the same as a concrete block?
Not quite. Cinder blocks used coal cinders as aggregate and are lighter. Most blocks sold today are concrete blocks (CMU), but the names are used interchangeably.