Stone Veneer Calculator

Stone veneer calculator formula

A stone veneer calculator turns the area of your wall into a number of boxes. Boxes = wall area ÷ coverage per box, rounded up. The tool uses 10 sq ft per box of flats, and a checkbox adds 10 percent for cuts and breakage before the rounding. Cost = boxes × price per box, with $180 as the starting price.

The formula in plain words

Multiply the wall width by the wall height. Divide by the area one box covers. Round up, since boxes are not split. If you tick the extra box, multiply the area by 1.1 first.

Worked examples

These match the calculator exactly.

1. Accent wall: 20 ft × 8 ft, $180 per box

• Area: 160 sq ft
• Boxes: 160 ÷ 10 = 16
• Cost: 16 × $180 = $2,880
• With 10% extra: 176 sq ft ÷ 10 = 17.6, rounded up to 18 boxes, $3,240

2. Fireplace surround: 12 ft × 9 ft, $180 per box

• Area: 108 sq ft
• Boxes: 108 ÷ 10 = 10.8, rounded up to 11, $1,980
• With 10% extra: 118.8 sq ft ÷ 10 = 11.88, rounded up to 12 boxes, $2,160

Notice that the extra 10 percent adds two boxes to example 1 but only one to example 2, because of the rounding.

What to order besides flats

Item	How it is sold	How to count
Flat pieces	Boxes of 10 sq ft in this tool	Wall area ÷ 10
Corner pieces	Boxes or linear foot	Total height of outside corners
Mortar and lath	By the bag and sheet	Per the maker’s guide
Water barrier and flashing	By the roll	Wall area plus laps
Sealer	By the gallon	Per the label

Corner pieces are shaped to wrap an outside corner. A wall with four corners of 8 ft each needs 32 ft of corners.

Coverage and product types

Coverage per box varies. Some brands sell boxes of 8 sq ft, 10 sq ft or 12 sq ft, and pieces that are easier to stack may be sold by the pallet. Natural and manufactured stone are priced differently, and installation methods differ. Read the box label and swap in the coverage if it differs from 10 sq ft. Divide your area by the label figure by hand.

How to measure

Measure the width and height of every wall you will cover and multiply to get the area. For a gable, measure the base and height and divide by 2. Subtract large windows and doors. A fireplace is often covered from the floor to the ceiling, so include the full height. Measure twice and write the numbers down.

Installing stone veneer

The wall needs a solid, clean surface that is prepared as the maker specifies, usually with a water barrier and metal lath for exterior walls. Mortar is applied to the back of each piece and the stones are pressed into place. Lay out the pieces dry on the ground first to blend color and shape. Work from the top down for a wet mortar method, so you keep the finished stone clean. Stone is heavy and a wall may need to support it, so check with the manufacturer and a contractor if you are covering a large area.

Planning the layout

Stone looks best when the colors are mixed. Pull pieces from several boxes at once so no patch of one color builds up. Lay a few rows on the ground first to see how the sizes fit. Plan cuts at the edges, where a cut stone is least visible, and leave a gap at the ground as the manufacturer advises so water can drain.

Weight and support

Veneer stone is lighter than full-thickness stone, but a wall of it still carries weight. Interior fireplaces and exterior walls are built to hold it, as long as the surface under it is sound. If you plan to apply it to a surface that was not built for it, check with the maker or a contractor first. Keep that in mind for tall or large installations.

Common mistakes

• Forgetting corner pieces.
• Assuming every brand covers 10 sq ft per box.
• Skipping the extra for cuts.
• Opening all boxes and mixing from one. Pull stones from several boxes for a better blend.
• Leaving out the barrier, lath and flashing.

Related pages

For brick, see the brick calculator. For stucco, see the stucco calculator. For mortar, see the mortar calculator.