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Stucco Calculator

Enter your wall area and stucco system. Get coat-by-coat bag estimates for 3-coat, 2-coat, 1-coat, and synthetic stucco systems.

Stucco Calculator
or calculate from dimensions
✓ Your estimate
Total stucco bags
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bags (80 lb)
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Scratch Coat Bags
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Brown / Base Bags
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Finish Coat Bags
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Wall Sq Ft

What this estimate includes

This calculator estimates 80-lb or 50-lb bags of stucco material for each coat of your chosen system. Coverage rates are based on typical application thickness per coat. Subtract window and door openings from your wall area before entering it for the most accurate estimate.

How it's calculated

Bags per coat = (area × waste factor) ÷ coverage per bag 3-coat: scratch 28 sq ft/80lb · brown 38 sq ft/80lb · finish 55 sq ft/80lb 2-coat: brown 32 sq ft/80lb · finish 55 sq ft/80lb 1-coat: 40 sq ft/80lb · Synthetic: base 50 sq ft/80lb · finish 65 sq ft/80lb 50 lb bags: coverage = 80 lb coverage × (50 ÷ 80)

Worked example

Example: 600 sq ft wall, 3-coat traditional, 80 lb bags, 10% waste

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Adjusted area: 600 × 1.10 = 660 sq ft
2
Scratch coat: 660 ÷ 28 = 23.6 → 24 bags of 80 lb
3
Brown coat: 660 ÷ 38 = 17.4 → 18 bags of 80 lb
4
Finish coat: 660 ÷ 55 = 12.0 → 12 bags of 80 lb
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Total: 24 + 18 + 12 = 54 bags

Before you buy

Buying tips

  • Subtract all window and door openings from your wall area before calculating — this is the single biggest source of over-ordering.
  • Scratch and brown coat bags are heavy. Plan delivery access and confirm weight limits if using scaffolding.
  • Buy scratch and brown coat from the same manufacturer as your finish coat for compatibility.
  • For color finish coats, buy all bags from the same lot number — color can vary slightly between production runs.
  • Keep stucco bags dry and off the ground until use; moisture in the bag accelerates set and ruins the material.
  • Mix scratch and brown coats stiff enough to hold shape when squeezed — too wet causes shrinkage cracks.

Frequently Asked Questions

How many bags of stucco do I need for 500 square feet?
For a 3-coat traditional system on 500 square feet, you need approximately 18 bags of scratch coat, 13 bags of brown coat, and 9 bags of finish coat — about 40 bags total in 80-lb bags. A 1-coat system over the same area needs roughly 13 bags of 80-lb material. Always add 10 percent waste for spillage and coverage variation.
What is the difference between 3-coat and 1-coat stucco?
3-coat stucco consists of a scratch coat keyed into lath, a brown coat leveled flat, and a finish coat with texture or color — it is the most durable system and is required by code over wood framing in many jurisdictions. 1-coat stucco is a single thicker layer applied over mesh lath; it is faster and less expensive but generally considered less crack-resistant than a full 3-coat system over time.
How thick is each coat of traditional stucco?
The scratch coat is applied at about 3/8 inch and raked (scratched) before it fully sets to create a mechanical bond for the next layer. The brown coat is applied at 3/8 inch once the scratch coat has cured, and it is floated flat. The finish coat is applied thinly at about 1/8 inch and is the decorative layer that provides the final texture and color.
What is synthetic stucco or EIFS?
Synthetic stucco (EIFS — Exterior Insulation and Finish System) uses rigid foam insulation board adhered to the substrate, followed by a fiberglass mesh-reinforced base coat and an acrylic finish coat. EIFS provides far better insulation than traditional stucco but requires careful detailing around windows and penetrations to prevent moisture intrusion. It is not a DIY-friendly system; professional installation is strongly recommended.
How long do I need to wait between stucco coats?
The scratch coat must cure for at least 48 hours before the brown coat is applied, and many specifications require 7 days for the scratch coat to fully hydrate and shrink. The brown coat must cure for at least 7 days — and up to 28 days in cooler weather — before the finish coat is applied. Rushing between coats is the most common cause of stucco cracking.
Can I apply new stucco over existing stucco?
You can apply a new finish coat over existing stucco if the existing surface is sound, clean, and firmly bonded to the substrate. If the existing stucco is cracked, delaminated, or soft, it should be removed before re-stuccoing. For a full re-stucco, a bonding agent is applied first, then the base and finish coats. You cannot safely apply a 3-coat system over existing stucco as the combined thickness becomes too heavy.
How much waste should I plan for in a stucco project?
Add 10 percent waste for straightforward rectangular walls with few penetrations. Add 15 percent for walls with many windows, doors, corners, or complex shapes where material is wasted on cuts and edges. Waste is also generated by mixing — stucco that sets in the bucket or on tools is lost material. First-time applicators should add at least 15 to 20 percent.
Disclaimer: This calculator provides planning estimates only. Actual stucco quantities depend on substrate condition, application thickness, applicator technique, and temperature. Always verify final quantities with your stucco supplier before purchasing. See all outdoor calculators.