Deck Stain Calculator

Estimate deck stain requirements based on deck size, wood type, and surface condition. Calculates separate amounts for horizontal surfaces, railings, and stairs.

Deck Stain Calculator

Calculate exact stain quantities based on industry research

Deck Dimensions

feet
feet
Deck Surface Area
0 sq ft

Deck Railing

Include

Stairs

Include

Landings

Include

Support Posts

Include

Deck Underside + Structure

Include

Wood & Stain Details

Understanding Coverage Rates

Key Factors That Affect Coverage:

  • • Surface Texture: Rough wood uses 50-100% more stain than smooth
  • • Wood Species: Softwoods need 2-3× more than dense hardwoods
  • • Wood Condition: Weathered wood absorbs 40% more than new wood
  • • Previous Coating: Maintenance coats cover 50-100% more area
  • • Application Method: Spray wastes 25-40%, brush only 5-10%

Research-Based Coverage Ranges:

  • • Solid stain: 200-400 sq ft/gal (first coat)
  • • Semi-transparent: 100-650 sq ft/gal (varies widely)
  • • Transparent/clear: 150-600 sq ft/gal
  • • Oil-based penetrating: 75-400 sq ft/gal
  • • Dense hardwoods: 350-450 sq ft/gal (ipe, cumaru)
  • • Second coats: Cover approximately 2× first coat area

Important: This calculator uses conservative estimates based on industry research showing field coverage is typically 20-40% lower than manufacturer specifications. Coverage rates account for wood absorption, surface texture, condition, and application method waste.

Frequently Asked Questions

How much deck stain covers per gallon?

Solid stains cover 200-400 square feet per gallon. Semi-transparent stains have the widest range at 100-650 square feet per gallon depending on wood porosity. Clear sealers cover 250-350 square feet per gallon. Rough or weathered wood requires 20-50% more stain than smooth, new wood.

How many coats of deck stain should I apply?

Most deck stains require 2 coats for proper protection. Solid stains may achieve full coverage in 1-2 coats. Semi-transparent and clear sealers typically need 2 coats. Weathered or bare wood may require 3 coats for adequate penetration and protection.

What's the difference between deck stain and sealer?

Solid stains provide opaque color like paint but allow wood texture to show. Semi-transparent stains add color while showing wood grain. Clear sealers provide UV and moisture protection without changing wood color. All types penetrate wood rather than forming a surface film.

How often should I restain my deck?

Clear sealers need reapplication every 1-2 years. Semi-transparent stains last 2-3 years. Solid stains last 3-5 years. Factors affecting lifespan include sun exposure, foot traffic, climate, and wood type. Reapply when water no longer beads on the surface.

Industry Standards Referenced

Last verified: November 2025

ASTM D3023 - Practice for Preservation of Wood(ASTM D3023)

View Standard

Standards for wood preservation treatments including proper preparation, application methods, and maintenance schedules for exterior wood structures. Covers both pressure-treated and naturally durable woods.

Key Requirements:

  • •Surface preparation: Clean, dry wood (moisture content ≤15%) before staining
  • •Weathered wood: Brighten with oxalic acid or wood brightener before staining
  • •End-grain treatment: Extra coat required on cut ends (absorbs 3× more)
  • •Application temperature: 50-90°F, no rain forecast within 24 hours
  • •Drying time: 24-48 hours between coats depending on temperature/humidity
Applies to:All exterior wood staining and sealing projects

ASTM D1413 - Testing Wood Preservatives by Lab Soil-Block(ASTM D1413)

View Standard

Test method for evaluating effectiveness of wood preservatives against decay fungi. Helps determine appropriate treatment for different exposure conditions.

Key Requirements:

  • •Ground contact: ACQ, CA, or MCQ pressure-treated wood required
  • •Above ground: Lesser treatments acceptable (.40 retention vs .60 for ground)
  • •Naturally durable: Cedar, redwood, ipe need no treatment but benefit from sealing
  • •Stain penetration: Pressure-treated wood requires 6-12 month weathering before staining
Applies to:Deck lumber selection and treatment requirements

Western Red Cedar Lumber Association (WRCLA) Finishing Guidelines(WRCLA Standards)

View Standard

Best practices for finishing cedar decking and outdoor structures. Cedar's natural oils affect stain absorption and require specific preparation methods.

Key Requirements:

  • •New cedar: Allow 2-4 weeks weathering before staining (natural oils prevent absorption)
  • •Mill glaze removal: Lightly sand or power wash before staining new cedar
  • •Clear sealers recommended: Let natural beauty show, reapply annually
  • •Semi-transparent stains: Work best on cedar, solid stains hide grain
  • •Maintenance: Re-stain every 2-3 years in high UV areas, 3-5 years in shade
Applies to:Cedar deck staining and maintenance

Manufacturer Application Instructions(Varies by Product)

Stain and sealer manufacturers provide specific application instructions that must be followed for warranty coverage. Coverage rates, drying times, and preparation requirements vary significantly between products.

Key Requirements:

  • •Surface prep: Most require clean, dry wood (some specify pressure washing)
  • •Temperature range: Typically 50-90°F surface temp, check specific product
  • •Coverage rates: Verify with product - range from 100-400 sq ft/gal
  • •Recoat timing: Usually 24-48 hours for water-based, 48-72 for oil-based
  • •Warranty: Following instructions exactly required for warranty claims
Applies to:All deck stain products - always read and follow label

VOC Regulations for Exterior Stains(EPA 40 CFR Part 59, State Regulations)

View Standard

Federal and state regulations limit volatile organic compounds in stains and sealers. Some states have stricter requirements affecting product availability and performance.

Key Requirements:

  • •Federal EPA: 250 g/L for exterior stains (relatively lenient)
  • •California CARB: 100-250 g/L depending on stain type (strictest)
  • •OTC States: Some northeastern states follow California model
  • •Low-VOC impact: May require additional coats or different application method
  • •Oil vs. water-based: Water-based typically lower VOC, different penetration
Applies to:Stain product selection - check state requirements

American Wood Protection Association (AWPA) Standards(AWPA U1 (Use Category))

View Standard

Standards for preservative treatment of lumber based on exposure category. Determines appropriate treatment retention levels for different deck components.

Key Requirements:

  • •UC2 (Above ground, protected): Joists under roof - .25 retention
  • •UC3A (Above ground, exposed): Deck boards, railings - .40 retention
  • •UC3B (Above ground, heavy wetting): Horizontal surfaces - .40 retention
  • •UC4A (Ground contact, general): Posts - .60 retention
  • •UC4B (Ground contact, critical): Posts in concrete - .60 retention
Applies to:Pressure-treated lumber selection and proper use category

Standards Disclaimer: Standards and codes are subject to periodic updates. Always verify current requirements with local building authorities and professional engineers before beginning construction. Links provided are for reference only.

📚

Want to Learn More?

Coverage rates for solid, semi-transparent, and clear stains with ASTM standards for wood preparation and application.

Read the Deck Stain Coverage Guide

How to Use This Calculator

  1. Enter deck dimensions: Input the deck area in square feet.
  2. Select wood type: Choose cedar, pressure-treated, or composite.
  3. Include railings & stairs: Enter linear feet if applicable.
  4. Review coverage: See gallons needed per coat based on wood porosity.

Deck Stain Coverage Rates

New wood absorbs more stain (150-200 sq ft/gal) than previously stained decks (250-300 sq ft/gal). Always apply 2 coats for proper protection.