Loading calculator...
Loading calculator...
Build perfect raised beds with our soil calculator. Calculate exact soil volumes, get custom soil mix recipes for different plants, and estimate material costs for your raised bed garden.
Nutrient-rich mix for heavy feeders
Raised beds offer superior drainage, warmer soil in spring, easier access (less bending), and better control over soil quality. They're ideal for areas with poor native soil, contaminated urban lots, or gardens with drainage problems. Our raised bed calculator determines soil volume needed, provides material estimates for construction, and calculates costs to help you plan your garden investment.
Optimal bed dimensions are 4 feet wide (reachable from both sides without stepping on soil), 8-12 feet long (manageable size), and 8-12 inches deep minimum (18-24 inches ideal for root crops). Cedar and redwood naturally resist rot without treatment; pine is cheaper but needs replacement in 5-7 years. Avoid railroad ties or pressure-treated lumber that may leach chemicals into food gardens.
Soil mix quality determines success. Don't use 100% compost (too rich, poor drainage) or garden soil alone (compacts in raised beds). Our calculator provides proven mix recipes: Mel's Mix (1/3 compost, 1/3 peat moss or coco coir, 1/3 vermiculite), Basic Mix (40% compost, 40% topsoil, 20% drainage amendment), or Budget Mix (50% topsoil, 30% compost, 20% perlite). Calculate volume in cubic feet, then order materials.
Installation tips: Level the bed location (use string and level—unlevel beds leak soil). Line bottom with hardware cloth to prevent burrowing animals. Fill incrementally, watering and allowing settling between layers. Expect 10-15% settling in first season. Add mulch layer to suppress weeds and retain moisture. Plan paths between beds wide enough for wheelbarrow access (2-3 feet minimum). With proper construction and soil, raised beds produce for decades.
8-12 inches minimum for most vegetables; 18-24 inches ideal for root crops (carrots, potatoes). Deeper beds hold more moisture and provide better root space but require more soil (higher cost). Shallow-rooted crops (lettuce, herbs) thrive in 6-8 inch beds. Our calculator adjusts soil volume based on your chosen depth.
Line the bottom with hardware cloth (1/4 inch mesh) to prevent burrowing animals. Don't use solid barriers—beds need drainage. Landscape fabric isn't necessary and can restrict beneficial soil organisms. On contaminated soil, use thick cardboard layer before filling to prevent root contact with contaminated ground.
Costs vary by location and materials. Budget $3-6 per cubic foot for quality soil mix. A 4x8x1 foot bed needs 32 cubic feet (~$100-200). Bulk delivery is cheaper than bagged soil. Our calculator estimates costs based on your bed dimensions and provides recipes for different budgets.