One 80 lb bag of mortar mix lays up to 13 standard concrete blocks or up to 37 standard bricks. These figures are from the QUIKRETE Mortar Mix data sheet.
Bags of mortar by number of blocks
| Blocks (8 × 8 × 16 in) | 80 lb bags of mortar mix |
|---|---|
| 25 | 2 |
| 50 | 4 |
| 100 | 8 |
| 150 | 12 |
| 200 | 16 |
| 300 | 24 |
Bags of mortar by number of bricks
| Standard bricks | 80 lb bags of mortar mix |
|---|---|
| 100 | 3 |
| 250 | 7 |
| 500 | 14 |
| 1000 | 28 |
The data sheet says “up to”, which is a best case. Joint thickness, waste on the board and how full you lay the bed all reduce it. Round up and buy at least one extra bag.
Water for mortar mix
| Bag size | Starting water | Maximum expected |
|---|---|---|
| 80 lb | about 5 quarts (4.7 L) | under 6 quarts (5.7 L) |
| 60 lb | about 3¾ quarts (3.5 L) | under 4½ quarts (4.3 L) |
Mortar is not concrete
Mortar has no gravel and is made for bonding masonry units. For slabs, footings and posts you need concrete mix. See cement vs concrete.
To count the blocks first, use the concrete block calculator.
Frequently asked questions
How many blocks does a bag of mortar lay?
Up to 13 standard 8 × 8 × 16 inch blocks per 80 lb bag of mortar mix, according to the manufacturer’s data sheet.
How many bricks does a bag of mortar lay?
Up to 37 standard bricks per 80 lb bag of mortar mix, according to the manufacturer’s data sheet.
How much water does a bag of mortar mix need?
About 5 quarts for an 80 lb bag and about 3¾ quarts for a 60 lb bag, with a maximum a little above that. Follow the directions on your bag.