Raised Bed Size Calculator
Get the right depth and width for what you're growing, then the exact amount of soil to fill it — two free tools in one.
1. Find your ideal dimensions
Raised Bed Size Advisor
Tell us what you'll grow and we'll suggest the right dimensions.
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See recommended beds on Amazon →2. Then calculate the soil
Raised Bed Soil Calculator
Enter inside dimensions to estimate base fill volume and bag count.
Supplier-quote scenarios — not prescriptions
- Penn State 70/30 starting point: — cu ft quality soil + — cu ft finished compost
- OSU up-to-25% compost scenario: — cu ft soil/planting mix + — cu ft finished compost
Use these only to request comparable quotes. Actual material depends on soil texture, compost analysis, drainage, crop, bed design, and a soil test. Do not fill the bed with compost alone.
Enter the bed's inside dimensions to compare bagged and bulk supply.
Compare bagged mix for a small project → Add frame, delivery, and accessories →The 3 numbers that matter
Depth — match it to your roots: 6–8 inches for greens, 12 for most vegetables, 18+ for root crops. Width — never more than 4 ft (or 2–3 ft against a wall) so you can reach the middle. Length — whatever fits; 8 ft is standard, brace anything longer. Full breakdown in our raised bed size guide.
Frequently asked questions
What is the best size for a raised garden bed?
A 4×8 ft bed is the most popular because lumber and kits come in those sizes and you can reach the middle from either side. Keep beds 4 feet wide or less so you never have to step in.
How deep should a raised garden bed be?
Use 6–8 inches for greens and herbs, 12 inches for most vegetables, and 18 inches or more for carrots, potatoes, and big tomatoes. The advisor above recommends a depth based on what you grow.
How wide should a raised bed be?
No wider than 4 feet if you can reach from both sides, or 2–3 feet if it sits against a wall or fence. This keeps every plant within arm’s reach so you never compact the soil by stepping in.
How long can a raised bed be?
Length is flexible — 8 feet is standard. Longer beds can bow outward, so add a center cross-support on anything over 8 feet.