Mortar Calculator
Enter how many bricks or blocks you're laying and the calculator gives you the bags of premixed mortar to buy. Get the unit count from the brick or block calculator, then size the mortar here.
Results
How the mortar calculator works
Mortar is estimated per unit laid. A standard 80 lb bag of premixed mortar lays roughly 30–37 bricks or about 33 concrete blocks with the usual face-shell bedding. Full bedding — mortar across the whole block — uses about twice as much, so a bag drops to around 17 blocks.
Formula: bags = number of units ÷ units per bag (rounded up)
| Job | 80 lb bag | 60 lb bag |
|---|---|---|
| Standard brick | ≈ 33 bricks | ≈ 25 bricks |
| Block — face-shell bedding | ≈ 33 blocks | ≈ 25 blocks |
| Block — full bedding | ≈ 17 blocks | ≈ 13 blocks |
Premixed vs. job-mixed mortar
- Premixed bags (cement, lime and sand already blended) are the simplest — add water and go. Type N is fine for most above-grade walls; type S is stronger for foundations and load-bearing work.
- Job-mixed mortar stretches further per dollar on big jobs: one bag of masonry cement plus roughly a cubic foot of masonry sand lays a similar number of units to a bag of premix.
- Only mix what you can lay in about 90 minutes — mortar that has started to set can't be re-tempered indefinitely.
- Buy a bag or two extra: parging, pointing and dropped mortar always eat into the total.
Frequently asked questions
How many bricks does a bag of mortar lay?
One 80 lb bag of premixed mortar lays about 30–37 standard bricks — roughly 33 on average. A 60 lb bag lays about 25. Job-mixed mortar with masonry cement and sand works out similarly.
How much mortar do I need for 100 blocks?
About 3 bags of premixed 80 lb mortar for 100 concrete blocks with face-shell bedding. Full bedding roughly doubles that to around 6 bags per 100 blocks.
How many bags of mortar per 1000 bricks?
Around 30 bags of premixed 80 lb mortar for 1,000 standard bricks. If you mix your own, plan on roughly 7 bags of masonry cement plus about a ton of masonry sand.
What is the difference between type N and type S mortar?
Type N is a medium-strength general-purpose mortar for most above-grade walls. Type S is stronger and bonds better, used for foundations, retaining walls and other load-bearing or below-grade masonry.