Cedar Lumber Calculator FAQ: Questions Answered
Estimating cedar comes down to a few numbers: the structure’s dimensions, the actual face width of your boards, the gap between them, and a waste factor that matches the grade. This page answers the most common questions about the Cedar Lumber Calculator, from how many pickets a fence needs to why your fasteners must be stainless steel.
How many pickets do I need for a 100-foot cedar fence?
About 209 six-foot 1×6 pickets. A 100 ft run is 1,200 inches; each picket covers its 5.5 in actual face plus a 1/4 in gap, or 5.75 in. Divide 1,200 by 5.75 and round up: 209 pickets, which is 1,254 linear feet. With the standard 10% waste allowance for STK-grade cedar, order 230 pickets (1,380 linear feet). In metric, the same fence is 30.48 m with each picket covering 146 mm: 30.48 ÷ 0.14605 = 208.7, rounded up to 209 pickets. The Cedar Lumber Calculator performs this same calculation for any run length.
What is the formula for estimating cedar decking?
Linear feet ≈ deck area in square feet × 2.2, for 5/4×6 decking (5.5 in face plus 1/4 in gap), then multiply by (1 + waste %). A 16 × 12 ft deck is 192 sq ft; 192 × 2.2 = 422 linear feet, and with 10% waste about 465 linear feet. In metric, multiply square meters by about 7.2: an 18 m² deck needs roughly 130 linear meters before waste. A full derivation of the 2.2 and 7.2 factors appears in the Cedar Lumber Calculator: Formula Explained guide.
How much waste should I add to a cedar estimate?
It depends on the grade: 5–10% for clear and A&BTR grades on straight runs, 10% for typical STK-grade fence and deck work, and 10–15% for knotty grades where you cut around defects. Knotty stock wastes more because each rejected knot costs 6–12 in (15–30 cm) of board. Apply the waste factor once, at the end of the calculation — not per line item — to avoid compounding the padding.
Do I use nominal or actual board dimensions?
Actual, always. A nominal 1×6 measures 3/4 in × 5-1/2 in (19 × 140 mm); a 5/4×6 deck board measures 1 × 5-1/2 in (25 × 140 mm); a 2×4 measures 1-1/2 × 3-1/2 in (38 × 89 mm). The one exception is board-foot pricing, where the trade conventionally uses nominal sizes. For board counts and linear feet — the numbers that determine your order — actual face width is the input.
What grade of cedar should I buy?
Match the grade to the application: STK (select tight knot) for fences and pergolas, A&BTR or better for deck surfaces and siding, clear heart only where a flawless face justifies the 40–80% premium. Buying clear grade for a fence is the classic overspend; buying knotty stock for siding is the classic underbuy, since knots bleed and check on exteriors. The Cedar Lumber Calculator: Material Guide maps every grade to its best use.
Why must cedar fasteners be stainless steel?
Cedar contains natural tannins and extractives that react with iron in standard steel or electro-galvanized fasteners, producing black iron-tannate streaks that bleed down the face of every board. The staining is permanent and appears within weeks of the first rain. Use 304 stainless steel screws for decking and fencing (316 near saltwater); hot-dip galvanized is acceptable for hidden framing connections. Pre-drill near board ends, since cedar splits easily.
How much does a cedar fence cost?
Costs vary widely by region and grade, so only planning ranges are meaningful: roughly $1,800–$2,900 in materials for 100 linear feet of 6-ft STK cedar privacy fence (pickets, posts, rails, stainless fasteners, post concrete, and stain), before labor. Cedar pickets typically run $3.50–$6.00 each; cedar decking $2.50–$4.00 per linear foot in STK. Cedar is cheapest near Pacific Northwest mills and notably pricier in the Southeast and Northeast. Get per-unit prices from two or three local yards and multiply by your calculator quantities — the Cedar Lumber Calculator: Cost Guide has full project breakdowns.
Should I stain cedar or let it weather gray?
Both are legitimate — the mistake is drifting between them. To keep cedar’s warm color, apply a penetrating UV-inhibiting semi-transparent stain within 2–4 weeks of installation, with a maintenance coat every 2–4 years. To go gray, simply leave it unfinished; the silver-gray patina is even and attractive as long as the whole structure weathers together. Once cedar has silvered, stain will not adhere properly until the weathered layer is removed by washing or sanding — so finishing late means refinishing, not just finishing.
Can cedar posts go directly in the ground?
It is not recommended. Cedar is rot-resistant, not rot-proof, and posts buried in soil rot at the ground line years before the above-grade wood shows wear — especially in wet climates. Set posts in concrete poured above grade, use standoff post bases, or keep the wood-to-soil transition inside concrete or metal. For the below-grade portion of a fence or deck, pressure-treated lumber rated for ground contact is the standard choice even on otherwise all-cedar projects.
Do I need a permit for a cedar fence or deck?
Often, yes — but the rules are entirely local. Many jurisdictions require permits for decks (especially attached or elevated ones) and regulate fence height (commonly 6 ft max in back yards, 4 ft in front) and placement relative to property lines. Because only the local authority having jurisdiction can give a definitive answer, verify with the building department before you buy lumber. The Cedar Lumber Calculator: Code Compliance guide covers what to ask and what documentation is typically involved.
DIY or hire a pro for a cedar project?
A ground-level cedar fence is one of the most DIY-friendly lumber projects: a 100-ft run is typically a long weekend for two people with basic tools. Decks get more demanding with height, ledger attachments, and footings — elevated or attached decks are where most homeowners hire out. Pergolas sit in the middle: simple to frame, but heavy timbers need extra hands. The Cedar Lumber Calculator: DIY vs. Pro guide breaks down the trade-offs by project type, including realistic time estimates.
How accurate is the calculator?
The calculator’s math is exact — board counts from your dimensions, the waste multiplier, and standard conversions — but it is a planning estimate, not a guaranteed quantity. Real projects involve variables no calculator can see: site irregularities, board defects, cutting mistakes, and grade variation within a lot. Treat the output as a planning figure, hand-check the board count with the formula, and confirm quantities with your supplier before ordering — especially on large or structural projects.
Estimate your cedar
Enter your project dimensions, board size, and a grade-appropriate waste allowance, and the Cedar Lumber Calculator returns board counts, linear feet, and board feet in metric or imperial. Figures are estimates; verify with your supplier before ordering.
Related Guides
- Cedar Lumber Calculator: The Complete Guide — full overview of cedar estimating, terms, and a worked fence example.
- Cedar Lumber Calculator: Cost Guide — cedar vs. pressure-treated vs. composite pricing and project budgets.
- Cedar Lumber Calculator: Formula Explained — the math behind board counts, linear feet, and waste.
- Cedar Lumber Calculator: Material Guide — cedar species, grades, and rough vs. surfaced stock.
- Cedar Lumber Calculator: DIY vs. Pro — when to DIY and when to hire, by project type.
- Cedar Lumber Calculator: Pre-Order Checklist — everything to verify before placing the order.
Get Your Number
Every answer above points to the same next step: measure your project, pick your grade, and run the numbers. The Cedar Lumber Calculator turns your dimensions into board counts, linear feet, and board feet in metric or imperial — verify the output against the formulas, then confirm with your supplier before ordering.
Disclaimer: Calculator results are planning estimates based on the dimensions you enter. Actual material needs vary with site conditions, product availability, and local pricing. Verify quantities with your supplier and consult a licensed professional for structural or code-related decisions.
