How many bags of mortar per 100 bricks (and per 100 blocks)?
3 bags of 80 lb mortar mix per 100 standard bricks, or 4 bags of 60 lb, from the label yield of 37 bricks per 80 lb bag plus 10% waste. For 8 x 8 x 16 in concrete blocks it is 9 bags of 80 lb per 100 blocks (13 blocks a bag). Measured as joint geometry instead, 100 solid modular bricks with 3/8 inch joints hold only about 23 litres (0.81 cu ft) of mortar, well under what the label allows: the difference goes into brick cores, squeeze-out and the mortar board. Buy by the label; use the geometry to check a quote. The tables cover 100 to 2,000 bricks and blocks, both methods, and 25 kg bags for UK bricks.
Open the brick and block calculator
How many bags of mortar per 100, 500 or 1,000 bricks?
37 standard bricks per 80 lb bag and 27.8 per 60 lb bag, from the maker's data sheet, with 10% waste. Standard means about 8 x 2 1/4 x 3 5/8 in with a 3/8 in joint.
| Bricks | 80 lb bags | 60 lb bags | Dry mix (lb, 80 lb bags) |
|---|---|---|---|
| 100 | 3 | 4 | 240 |
| 250 | 8 | 10 | 640 |
| 500 | 15 | 20 | 1,200 |
| 1,000 | 30 | 40 | 2,400 |
| 2,000 | 60 | 80 | 4,800 |
How many bags of mortar per 100 to 2,000 blocks?
13 blocks per 80 lb bag and 9.8 per 60 lb bag, from the maker's data sheet for face-shell bedding, plus 10% waste.
| Blocks | 80 lb bags | 60 lb bags | Dry mix (lb, 80 lb bags) |
|---|---|---|---|
| 100 | 9 | 12 | 720 |
| 250 | 22 | 29 | 1,760 |
| 500 | 43 | 57 | 3,440 |
| 1,000 | 85 | 113 | 6,800 |
| 2,000 | 170 | 226 | 13,600 |
How much mortar actually fits in the joints?
The brick and block calculator works mortar out as the wall volume minus the volume of the units, per square metre of wall face, for solid units. Per 100 units, no waste:
| Unit | Units per m² | Mortar per m² (L) | Mortar per 100 units (L) | Mortar per 100 units (cu ft) |
|---|---|---|---|---|
| US modular brick, 3/8 in joint | 73.8 | 16.9 | 23 | 0.81 |
| 8 x 8 x 16 in block, 3/8 in joint | 12.1 | 13.4 | 111 | 3.91 |
| UK / EU brick 215 x 65 mm, 10 mm joint | 59.3 | 17.6 | 30 | 1.05 |
These are the floor. Cored bricks, frogged bricks and hollow blocks take mortar into the holes, and a site wastes more than a clean sum allows, which is why the label yields above come out higher. The block wall guide and the bricks per square foot guide give the unit counts to start from.
Mixing and buying
- An 80 lb bag is one wheelbarrow batch and lays about 37 bricks, roughly an hour's work for one bricklayer. Mix what you can use in 90 minutes; retempering old mortar weakens it.
- Over about 1,000 bricks, site-mixed mortar (1 part cement, 1 lime, 6 sand for type N) is cheaper than bags; start from the joint volume and add generously for cores and waste.
- Coloured mortar, wide or raked joints and soft, absorbent brick all use more than the label; keep the 10% and add a bag.
- Mortar is for laying; grouting the cores of a block wall is a different, wetter mix and a separate quantity.
UK bricks: 25 kg bags
215 x 65 mm bricks with a 10 mm joint, 59 per m². A 25 kg bag of ready-mixed mortar makes about 12.5 litres, a common figure on the bag; check yours. Joint volume for solid bricks with 10% waste.
| Bricks | Wall face (m²) | Mortar (L) | 25 kg bags |
|---|---|---|---|
| 100 | 1.7 | 33 | 3 |
| 500 | 8.4 | 163 | 14 |
| 1,000 | 16.9 | 327 | 27 |
| 2,000 | 33.8 | 654 | 53 |
Frogged and perforated bricks, which most UK bricks are, take mortar into the frog, so expect to use well above this table; treat it as the minimum and check the yield your merchant quotes. The bricks per square metre guide has the brick counts.
Frequently asked questions
- How many bags of mortar per 100 bricks?
- 3 bags of 80 lb or 4 of 60 lb with 10% waste. The maker's yield is 37 standard bricks per 80 lb bag; 100 / 37 = 2.7 bags, and the rounding covers what ends up on the ground. Thin bricks, wide joints and heavily cored bricks use more; check the yield on your own bag.
- How many bags of mortar per 100 blocks?
- 9 bags of 80 lb per 100 standard 8 x 8 x 16 in blocks (13 blocks a bag), or 12 of 60 lb, with 10% waste. That is for face-shell bedding, which is how block is normally laid; full bedding of the webs uses more. 500 blocks is 43 bags of 80 lb.
- How much mortar for 1,000 bricks?
- 30 bags of 80 lb or 40 of 60 lb pre-mixed mortar, about 2,400 lb of dry mix. At that quantity most masons mix from cement, lime and sand. The joints of 1,000 solid modular bricks hold about 8.1 cu ft (0.3 cubic yards) of mortar; budget well above that for cores and waste.
- How much mortar per square foot of brick wall?
- 6.86 modular bricks per square foot with about 0.055 cu ft of mortar in the joints; a 100 sq ft wall has 686 bricks and 5.5 cu ft in the joints, and by the label needs 21 bags of 80 lb. The brick calculator shows the joint mortar for any wall and any brick.
- Mortar mix or mason mix, type N or type S?
- Both are cement, lime and sand; the difference is strength. Type N (mortar mix) for above-grade walls, chimneys and anything exposed to weather where a little flexibility helps; type S (mason mix) for below grade, retaining walls, block foundations and anywhere it bears real load. The bag yields are the same for both, so the tables apply to either.
- Why does the label yield differ so much from the calculated volume?
- The label assumes a working wall: cored bricks that swallow mortar, full joints with squeeze-out, mortar dropped and scraped. The geometry counts only what stays in the joints of a solid brick. For 100 modular bricks that is 23 litres by geometry, so each labelled bag is putting only about 8 litres into the joints. Buy by the label; if a quote is far above it, ask why.
More guides
- How many bricks per square metre (and per square foot)?
Bricks and blocks per square metre and per square foot for the common formats, how the mortar joint changes the count, and what to order for a 10 m² wall.
- How many bricks per square foot? Walls, patios and floors
Modular bricks per square foot of wall (about 7) and laid flat on a patio (4.5 to 5), bricks for 100 to 500 sq ft with 5% waste, mortar, and the UK brick per sq ft.
- How many bricks do I need for a fire pit? 30, 36 and 48 inch
Bricks per course and in total for round fire pits of 30 to 48 in inside diameter at 3 to 5 courses, in modular, UK and fire brick sizes, with 5% waste, and square pits.
- How many blocks for a retaining wall? (12x4, 16x6 and 18x8 in)
Retaining wall blocks for 10 to 50 ft walls at 1, 2 and 3 ft high in the three common sizes, plus the gravel base and the drainage stone behind the wall, and metric.
Last updated 2026-09-13. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.