Stone Veneer Calculator
Calculate how many square feet and boxes of stone veneer you need for a wall, with corner pieces, mortar bags, metal lath and water-resistive barrier included.
By CalcBuilt Editorial TeamUpdated September 9, 2026Formulas checked against manufacturer specs, see how we calculate.
Results
- Flat stone to order
- 176 sq ft
- 160 sq ft of flats after openings and corners, plus 10% waste
- Boxes of flats
- 18 boxes
- At 10 sq ft per box
- Corner pieces
- 0 ft
- Sold by the linear foot; each foot of corner replaces about 0.75 sq ft of flat stone
- 80 lb bags of mortar
- 12 bags
- Scratch coat and setting bed at about 15 sq ft per bag, over 160 sq ft of wall. Grout for mortared joints is extra, about 45 sq ft per bag
- Metal lath sheets
- 10 sheets
- 27 in x 96 in sheets of 2.5 lb self-furring lath (18 sq ft each) including laps and waste; 1-1/2 in roofing nails into studs every 6 in
- Water-resistive barrier
- 320 sq ft
- Two layers of Grade D paper or house wrap over the sheathing, lapped shingle fashion. Add a 1/4 in drainage mat in wet climates
Stone Veneer formula
Wall area = Length x Height - openings
Flats = (Wall area - corner linear ft x 0.75) x (1 + waste %)
Boxes = Flats / sq ft per box, rounded up
Mortar bags = Wall area x (1 + waste %) / 15; Lath sheets = Wall area x (1 + waste %) / 18Worked example
A 30 x 9 ft garage wall with 40 sq ft of windows and two 9 ft outside corners: 30 x 9 = 270 sq ft, minus 40 = 230 sq ft of wall. The corners total 18 linear ft and replace 18 x 0.75 = 13.5 sq ft of flats, so flats = 216.5 sq ft. With 10% waste that is 238.2 sq ft, or 30 boxes at 8 sq ft. Corner pieces: 18 x 1.1 = 19.8, so buy 20 linear ft.
Mortar covers the whole 230 sq ft plus waste: 253 / 15 = 16.9, so 17 bags of 80 lb mortar. Lath: 253 / 18 = 14.1, so 15 sheets. The water-resistive barrier is two layers over 230 sq ft, or 460 sq ft.
Quick reference
| Wall area | Flats to order | Boxes | 80 lb mortar bags | Lath sheets |
|---|---|---|---|---|
| 100 sq ft | 110 sq ft | 11 | 8 | 7 |
| 200 sq ft | 220 sq ft | 22 | 15 | 13 |
| 300 sq ft | 330 sq ft | 33 | 22 | 19 |
| 400 sq ft | 440 sq ft | 44 | 30 | 25 |
| 500 sq ft | 550 sq ft | 55 | 37 | 31 |
How to measure for stone veneer
Multiply wall length by height and subtract windows and doors. Add every outside corner bottom to top in linear feet; each foot of corner replaces about three quarters of a square foot of flats. Add 10 percent for cuts and breakage and round up to whole boxes. The coverage on the box assumes a 1/2 inch grout joint; laying a jointed profile tight for a dry-stack look takes another 10 to 15 percent.
Flats come in 8 to 10 square foot boxes and corners in 5 to 10 linear foot boxes. Order from one lot and blend from three to five open boxes at a time. Special-order colors run 2 to 6 weeks with 15 to 25 percent restocking. Boxes weigh 40 to 70 lb, so a 20 box order comes on a lift-gate truck.
The wall system behind the stone
Over wood framing: sheathing, two layers of water-resistive barrier lapped shingle fashion, then 2.5 lb self-furring lath with the cups facing up. Nail the lath into studs every 6 inches with 1-1/2 inch roofing nails; nails into sheathing alone will not hold. The 1/2 inch scratch coat is scored horizontally and cures 48 hours before any stone goes on. In wet climates such as the Pacific Northwest and Gulf Coast, add a 1/4 inch drainage mat between barrier and lath (CMHA guide).
Use polymer-modified veneer mortar (ANSI A118.4) or Type S (ASTM C270) for both coats; a heavy back-butter drops coverage from 15 toward 10 square feet per bag. Set corners first, alternating long and short legs, then work toward the middle. Grouted joints go top down so drips land on bare scratch coat, then get raked when thumbprint hard; dry-stack goes bottom up. Keep the stone 4 inches above grade and 2 above paving, over a weep screed.
What this calculator leaves out
The result is stone, mortar, lath and barrier. Grout for mortared joints is separate, about 40 to 50 square feet per bag at 1/2 inch; dry-stack needs none. Also separate: weep screed, casing bead, lath nails, drainage mat, and window and kickout flashing. Adhered veneer at 15 lb per square foot or less needs no footing (IRC R703.12).
Mistakes that cost money
- Setting stone on a scratch coat that is hours old; it needs 48 hours to cure or the weight pulls it off the lath.
- Box coverage is quoted with a 1/2 in joint; laying a jointed profile tight for a dry-stack look takes 10 to 15% more stone.
- Corners set last never line up with the courses; set corners first, alternating long and short legs, and work toward the middle.
- Stone run to grade wicks water and effloresces; keep it 4 in above soil and 2 in above paving, over a weep screed.
- Muriatic acid burns the color off manufactured stone; brush off mortar smears when thumbprint hard and wash with granulated detergent.
- Lath nailed only into sheathing pulls loose under 10 lb per sq ft of stone; 1-1/2 in roofing nails go into studs every 6 in.
Key facts
- Adhered manufactured stone veneer weighs no more than 15 lb per sq ft installed, which is why it needs no footing or brick ledge.
- Corner pieces are L-shaped with a long and a short return leg; each linear foot covers about 0.75 sq ft that would otherwise need flats.
- The scratch coat over metal lath is nominally 1/2 in thick, scored horizontally, and cures 48 hours before stones are set.
- The IRC requires two layers of water-resistive barrier behind adhered stone veneer over wood framing (R703.12).
- A 27 x 96 in sheet of 2.5 lb self-furring lath covers 18 sq ft before laps; sheets overlap 1 in on the sides and 2 in on the ends.
Frequently asked questions
How many square feet of stone veneer do I need?
Multiply wall length by height, subtract openings and 0.75 sq ft per linear foot of corners, then add 10% waste. A 20 x 8 ft wall with no openings needs 176 sq ft of flats.
Does stone veneer need a footing or brick ledge?
Not for adhered veneer at 15 lb per sq ft or less, which covers manufactured stone and thin-cut natural stone under about 1-1/4 in; it hangs on the lath and mortar (IRC R703.12). Full-bed natural stone 3 to 5 in thick weighs 40 to 50 lb per sq ft and needs a brick ledge on the foundation under R703.8.
How much mortar for stone veneer?
Plan on one 80 lb bag of veneer or Type S mortar for every 15 sq ft of wall, which covers both the scratch coat and the setting bed. A 160 sq ft wall with 10% waste needs 12 bags.
Do I need lath behind stone veneer?
Yes over wood framing, sheathing, or painted masonry: use galvanized self-furring metal lath over two layers of water-resistive barrier. Over clean, unpainted concrete or block the stone can be set directly.
Sources and references
- Manufactured Stone Veneer Installation Guide (MSV-MAN-001) (Concrete Masonry & Hardscapes Association (formerly NCMA and MVMA))
- Chapter 7 Wall Covering, 2021 IRC (R703.12 adhered masonry veneer) (ICC)
- ASTM C1780 Standard Practice for Installation Methods for Adhered Manufactured Stone Masonry Veneer (ASTM International)
- QUIKRETE Veneer Stone Mortar product page (Quikrete)
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Results are estimates based on standard formulas and typical product specifications. Confirm quantities with your supplier and local code before ordering.