Imperial / Metric Converter
Deck-focused unit conversion utility. Linear (ft / in / yd / m / cm / mm), area (sqft / sqm), volume (cuft / cuyd / cum / gallons / liters), mass (lb / kg / tons / tonnes). Lumber nominal-to-actual covering 16 sizes from 1×2 through 6×6 (with 5/4×6 standard decking). 11 decking board profiles with metric mm + per-board sqft / sqm coverage. Coverage planner: target deck area (sqft OR sqm) → board count + linear feet / meters needed.
Inputs
16 feet → meters
All conversions
| From | To | Note |
|---|---|---|
| 16 16 feet | 4.8768 meters | |
| 16 16 feet | 192 inches | |
| 16 16 feet | 5.3333 yards | |
| 16 16 feet | 487.68 centimeters | |
| 16 16 feet | 4876.8 millimeters |
- Conversion uses NIST-published factors (2026-Q1). For lumber purchase, always round UP to next stocked length.
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Linear / area / volume / mass factors per NIST Special Publication 811. Lumber nominal-to-actual per ANSI/ALSC PS 20-15 American Softwood Lumber Standard. Decking board dimensions from manufacturer spec sheets (Trex / TimberTech / AZEK / Fiberon / Deckorators, 2026-Q1).
How to use
How to use the imperial / metric converter in 5 steps.
- 1
Pick a mode
Linear / area / volume / mass for generic conversions. Lumber for 2×4 → 38 × 89 mm style nominal-to-actual. Decking for Trex / TimberTech / AZEK board dimensions in mm + per-board sqft. Coverage planner for board-count math from a target deck area.
- 2
Linear / area / volume / mass
Enter a value + pick the FROM unit + pick the TO unit. Calculator returns the primary conversion plus all other unit equivalents (e.g. 16 ft = 4.877 m = 487.68 cm = 4876.8 mm = 5.333 yd).
- 3
Lumber nominal-to-actual
Pick a nominal size from 1×2 through 6×6 (16 sizes including 5/4×6 standard decking). Calculator returns the actual surfaced (S4S) dimensions in inches + millimeters + centimeters. 2×4 nominal → 1.5×3.5″ actual → 38×89 mm — the actual size you'll receive after planing.
- 4
Decking board dimensions
Pick from 11 stocked decking profiles — Trex / TimberTech / AZEK / Fiberon / Deckorators 1×6 + 1×8, plus PT 5/4×6 / cedar 5/4×6 / IPE 1×6. Pick a length (12 / 16 / 20 ft). Calculator returns mm dimensions + per-board sqft / sqm coverage.
- 5
Coverage planner
Enter target deck area (in sqft OR sqm), pick the board profile + length + waste factor (default 10%). Calculator returns board count + total linear feet + total linear meters needed for purchase planning.
How we calculate
How DeckMath calculates this — IRC 2021 sources.
The Imperial / Metric Converter is a deck-focused unit conversion utility covering 7 modes — linear (ft / in / yd / m / cm / mm), area (sqft / sqm), volume (cuft / cuyd / cum / gallons / liters), mass (lb / kg / tons / tonnes), lumber nominal-to-actual (1×2 through 6×6 → actual inches and millimeters), decking-board dimensions (Trex / TimberTech / AZEK / Fiberon / Deckorators / PT / cedar / IPE → metric mm + per-board sqft / sqm coverage), and a coverage planner (target area in sqft or sqm → board count + linear feet / meters needed with waste factor). All conversions use NIST-published factors.
IRC references
- ANSI/ALSC PS 20-15 — American Softwood Lumber Standard (nominal vs actual)
- NIST Special Publication 811 — Guide for the Use of the International System of Units
- IRC 2021 Appendix N — Imperial/SI conversion factors for residential codes
Linear / area / volume / mass factors per NIST Special Publication 811. Lumber nominal-to-actual per ANSI/ALSC PS 20-15 American Softwood Lumber Standard. Decking board dimensions from manufacturer spec sheets (Trex, TimberTech, AZEK, Fiberon, Deckorators, 2026-Q1).
NIST 'international foot' definition. So 16 ft = 4.877 m, 20 ft = 6.096 m, 1 yard = 0.9144 m. For lumber purchase, always round UP to next stocked length — half-boards are usually non-returnable.
Equivalently 1 sqm = 10.7639 sqft. A 240 sqft deck = 22.30 sqm. A 30 sqm deck = 322.92 sqft. Round up to nearest 5 sqft / 0.5 sqm when ordering decking.
Concrete in the US ships in cubic yards; in metric countries in cubic meters. A 3 cuyd ready-mix delivery = 2.29 m³. 1 US gallon = 3.785 liters (NOT the same as the Imperial gallon — UK Imperial gallon = 4.546 liters; this calculator uses US gallons).
Used for delivery freight planning + helicopter-lift weight checks on multi-story decks. 1 ton (US short ton) = 907.18 kg ≠ 1 metric tonne (1000 kg). A 16 ft 2×10 PT joist weighs ~50 lb / 22.7 kg.
Standard US softwood is sold nominal but surfaced (S4S — Surfaced on 4 Sides) to a smaller actual dimension. 2×4 nominal → 1.5×3.5″ → 38×89 mm. 5/4×6 (standard PT decking) → 1×5.5″ → 25.4×140 mm. Always check actual dimensions when matching to a structural span chart.
A 5.5″ wide × 16 ft Trex board covers (5.5 × 192) / 144 = 7.33 sqft. For a 240 sqft deck with 10% waste, that's ceil(240 × 1.10 / 7.33) = 37 boards. Total linear feet = 37 × 16 = 592 ft = 180.4 m.
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People also ask
Imperial / metric questions, answered.
US softwood lumber is sold by NOMINAL size — the rough-cut size before planing. After surfacing (S4S = Surfaced on 4 Sides), the lumber loses 1/2″ on each dimension for boards ≤2″ nominal thickness, and 3/4″ for thicker stock. A 2×4 starts as a rough 2×4 → planed to 1.5×3.5″ = 38×89 mm. A 6×6 post starts rough then planes to 5.5×5.5″ = 140×140 mm. Always use the ACTUAL dimensions when calculating spans, beam strength, or fitting hardware.
12 ft × 16 ft = 192 sqft = 17.84 sqm. Conversion: 1 sqft = 0.09290304 sqm exactly. Common sizes: 10×10 = 100 sqft = 9.29 sqm · 12×12 = 144 sqft = 13.38 sqm · 16×20 = 320 sqft = 29.73 sqm. The calculator gives you both directions automatically.
Trex 1×6 grooved boards are 0.94″ × 5.5″ × 16 ft → 23.88 × 140 mm × 4877 mm in metric. Trex 1×8 wide-board is 0.94″ × 7.25″ × 16 ft → 23.88 × 184 mm × 4877 mm. TimberTech 1×6 is slightly narrower at 5.36″ (136 mm) due to TimberTech's profile geometry. AZEK matches Trex at 5.5″. The calculator's decking mode covers all the major brands.
Use the coverage planner mode. Enter target area (sqft or sqm), pick the board profile + length + waste %. Math: boards = ceil(area × (1 + waste) / per_board_sqft). For 240 sqft with a 5.5″ × 16 ft Trex board (= 7.33 sqft / board) + 10% waste: ceil(240 × 1.10 / 7.33) = 37 boards = 592 linear ft = 180.4 linear m.
1 US gallon = 3.785 liters. 1 Imperial (UK) gallon = 4.546 liters — about 20% larger. The calculator uses US gallons (standard in North America for concrete, paint, sealant volumes). When ordering material from UK or Australian sources, convert through liters first to avoid the gallon ambiguity. Decking sealant volumes are typically US gallons in North-American spec sheets.
About 3 lb per linear foot for PT southern pine (density ~30 lb/cuft, actual cross-section 1.5×9.25″ = 13.9 sqin = 0.0965 sqft). So a 16 ft 2×10 PT = ~50 lb = ~22.7 kg. A 20 ft 2×12 PT = ~80 lb = ~36 kg. For helicopter-lift or stair-up-to-elevated-deck weight checks, use the calculator's mass mode to convert.
Metric lumber standards (Europe, Australia, NZ) are published in millimeters — e.g. 38×89 CLS, 45×95 SLP, 50×100 European softwood. Centimeters aren't used in the building trade. The calculator returns both mm + cm but mm is the practical unit. 38 mm = 3.8 cm = 1.5″.
Approximately yes — 1 m = 3.2808 ft. But metric decking is typically sold in standardized lengths: 3 m (9.84 ft), 3.6 m (11.81 ft), 4.2 m (13.78 ft), 4.8 m (15.75 ft), 5.4 m (17.72 ft), 6.0 m (19.69 ft). North-American decking comes in 8/10/12/16/20 ft. When matching a metric-spec deck to North-American supply, round UP to the next 16 or 20 ft length and accept the cutoff scrap.
1 m³ = 35.315 cuft. At a typical 80 lb bag yield of 0.60 cuft (Quikrete / Sakrete standard mix), 1 m³ needs ceil(35.315 / 0.60) = 59 bags before waste. With 10% waste = 65 bags. At that volume the Concrete Calculator's ready-mix breakpoint advisory triggers — delivered concrete is usually cheaper above 0.76 m³ (1 cuyd).
Yes — all factors are NIST-published exact values (where exact) or rounded to 7+ significant digits. 1 ft = 0.3048 m (exact); 1 lb = 0.45359237 kg (exact); 1 in = 25.4 mm (exact). The calculator rounds OUTPUT to 4 decimals max for display readability — internal math is full precision. For high-precision engineering work (over 1000 m³, or > 5000 sqm), use the NIST official table directly.
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