Board feet measures lumber volume. One board foot equals 144 in³.
- Core formula: BF = (T(in) × W(in) × L(ft)) ÷ 144
- Inches-only form: BF = (T × W × L(in)) ÷ 1728
- Quantity: BF_total = BF × Qty
- Kerf: BF_kerf = BF_total × (1 + Kerf%)
- Waste: BF_final = BF_kerf × (1 + Waste%)
- Cost: Cost = BF × Price_per_BF
- Choose units for thickness and width, then choose length unit.
- Enter thickness, width, length, and quantity for a quick total.
- Pick a species preset to suggest a realistic waste factor.
- Add kerf loss when you plan to cut boards into parts.
- Enter price per board foot to estimate your purchase cost.
- Use the multi-board list when your sizes vary by section.
- Press Calculate and download CSV or PDF for shopping notes.
| Use case | Board size | Qty | Kerf | Waste | Board feet | Note |
|---|---|---|---|---|---|---|
| Raised bed frame | 1 × 6 × 8 ft | 10 | 1% | 10% | ~3.67 | Good baseline for softwood boards. |
| Planter bench slats | 1 × 4 × 6 ft | 14 | 2% | 12% | ~3.05 | Extra waste helps sort warped pieces. |
| Garden edging | 2 × 2 × 4 ft | 16 | 0% | 8% | ~1.58 | Short cuts can reduce kerf loss. |
Purpose
Board-feet planning turns a cut list into a measurable volume that suppliers understand. This calculator converts thickness, width, and length into board feet, scales the result by quantity. It supports mixed units and performs internal conversion to inches for consistent math. Use it to compare alternative board sizes, and before purchase to validate your final list.
Waste
Garden projects often waste more lumber than indoor builds because boards can be bowed, checked, or wet. The waste factor field lets you add a percentage buffer so you can reject poor pieces at the yard. Typical ranges are 8–12% for straight framing, 12–15% for hardwood, and higher when you need clean, knot-free faces for benches or trellis slats.
Kerf
Kerf loss accounts for material removed by saw cuts. When you turn long boards into shorter parts, the blade eats length each cut and can add up across many pieces. A 1–3% kerf allowance is common for small projects. If you are ripping boards into narrower strips, increase kerf slightly and re-check totals with the multi-board list.
Cost
Price per board foot converts volume into a budget figure. Because stores may label lumber by nominal sizes, cost estimates work best when you measure actual thickness and width, or use typical actual dimensions from your supplier. Compare base cost to the final cost with kerf and waste so you can see how much contingency you are buying.
Workflow
Use the multi-board list for varied components like raised-bed sides, corner posts, and cap rails. Each row calculates board feet for that size and quantity, then totals everything into one purchase number. Export CSV for your shopping checklist and PDF for sharing with a supplier and helpers quickly.
For accuracy, set rounding to two or three decimals during planning and round up when ordering. Keep the currency label consistent for quotes. If you change units between entries, use the unit selectors rather than manual conversion. That reduces input errors and keeps your exported files traceable.
1) What is one board foot?
A board foot is a volume equal to 144 cubic inches, commonly represented as a 1-inch-thick board that is 12 inches by 12 inches.
2) Why does the calculator use inches internally?
Board-foot formulas are defined from inch-based volume. Converting everything to inches first keeps the math consistent across metric and imperial entries.
3) How should I choose a waste factor for garden lumber?
Use 8–12% for straight framing, 12–15% for hardwood, and higher when boards must be clear, straight, and appearance-grade for seating or trim.
4) When should I add kerf loss?
Add kerf when you will cut long boards into many parts. Small projects often use 1–3%. Increase slightly if you expect many rip cuts.
5) Should I use nominal or actual dimensions?
Use actual thickness and width whenever possible. Nominal sizes can overstate volume, which can skew both board-feet totals and cost estimates.
6) When is the multi-board list better than single inputs?
Use it when your project mixes sizes, like bed sides, posts, rails, and caps. Each row is totaled, helping you match a cut list to purchasing.