How Much Lumber and Soil for a Raised Bed?
Calculate lumber, screws, and soil needed to build a raised garden bed. Popular sizes from 4×4 to 4×12.
Best Raised Bed Dimensions
The most popular raised bed size is 4×8 feet — wide enough for 2-3 rows of plants and long enough for variety, but narrow enough to reach the center from either side without stepping in. Keep width at 4 feet maximum (3 feet if only accessible from one side). Height of 12 inches is ideal for most vegetables; 18-24 inches eliminates bending and is accessible for gardeners with mobility issues.
Best Wood for Raised Beds
Cedar: Naturally rot-resistant, no chemicals, lasts 10-15 years. The gold standard but most expensive. Redwood: Similar to cedar, slightly harder to find. Pressure-treated: Cheapest and longest-lasting (15-20 years), but some gardeners worry about chemicals leaching into soil. Modern PT lumber uses ACQ (alkaline copper quaternary) which the EPA considers safe for food gardens. Avoid: untreated pine (rots in 2-3 years), railroad ties (contain creosote), and pallets (may be chemically treated).
Soil Mix for Raised Beds
The ideal raised bed soil mix: 1/3 topsoil, 1/3 compost, 1/3 drainage material (perlite, vermiculite, or aged bark). Do not fill with garden soil alone — it compacts too much in a raised bed. Pre-mixed "raised bed soil" from landscape suppliers typically costs $45-65 per cubic yard. One cubic yard fills approximately one 4×8×12" bed.
A 4×8×12" raised bed requires approximately 1 cubic yard of soil mix. Filling it with bagged soil from a hardware store (at $5-6 per 40-lb bag) would cost $150-180. Bulk delivery from a landscape supplier costs $55-65 for the same volume — a 60-70% savings.
