Vegetable Garden Yield & Raised Bed Soil Calculator

Calculate Soil Volume, Plant Spacing, and Growing Season Harvest Yields

Growing your own fresh vegetables is rewarding, economical, and healthy. To ensure success, you need to calculate the volume of rich organic soil required to fill your raised beds and space the plants correctly to avoid overcrowding. Use this calculator to determine soil requirements, estimate plant counts, and project your home garden harvest yield in pounds.

Bed Length (ft):
Bed Width (ft):
Bed Soil Depth (in):
Number of Garden Beds:
Primary Vegetable Crop:	Tomatoes (Slicing/Roma) Bell Peppers Head / Leaf Lettuce Carrots (Root Crop) Zucchini / Summer Squash
Bag Size Preference:	1.5 Cubic Feet bags 2.0 Cubic Feet bags 3.0 Cubic Feet bags (bulk bale)

Raised Bed Garden Soil Calculation & Mel's Mix Formula

Filling a raised garden bed with ordinary dirt from your yard is a recipe for compaction and poor root growth. Home gardeners prefer a lightweight, organic soil mixture that retains water while draining well. One of the most popular recipes is **"Mel's Mix"** (from Square Foot Gardening):

• 1/3 Organic Compost: Provides essential nutrients and microbes (blend 3-5 different sources of compost for nutrient diversity).
• 1/3 Coarse Vermiculite: A natural mineral that expands to retain moisture and keep the soil fluffy.
• 1/3 Peat Moss (or Coco Coir): Retains water and aerates the soil structure.

To calculate the total volume of soil needed for any raised garden beds, use this formula:

• $$\text{Volume per Bed (cu.ft.)} = \text{Length} \times \text{Width} \times \frac{\text{Depth}}{12}$$
• $$\text{Total Volume (cubic yards)} = \frac{\text{Volume per Bed} \times \text{Bed Count}}{27}$$

Vegetable Spacing Guidelines & Seasonal Yield Expectations

Vegetable Crop	Spacing Required	Plants per Sq.Ft.	Est. Yield per Plant
Tomatoes (Staked)	24 inches apart	0.25 (4 sq.ft / plant)	10 to 20 lbs
Bell Peppers	18 inches apart	0.44 (2.25 sq.ft / plant)	5 to 10 lbs
Head / Leaf Lettuce	10 inches apart	1.44 (0.7 sq.ft / plant)	1 to 1.5 lbs
Carrots	3 inches apart	16 (0.06 sq.ft / plant)	0.2 lbs (1 carrot)
Zucchini	36 inches apart	0.11 (9 sq.ft / plant)	8 to 15 lbs

Building a Rich Raised Garden Bed Soil Blend

Purchase high-quality ingredients in bags or bulk cubic yards. If mixing your own organic blend, we suggest utilizing equal parts compost, peat moss, and vermiculite as calculated below. Raised beds dry out faster than in-ground gardens, so laying down a thick 2-inch layer of organic straw or wood shaving mulch on top of the soil will reduce evaporation by up to 50%.

Frequently Asked Questions

Why use raised garden beds instead of planting in the ground?

Raised beds offer superior control over soil quality, eliminate soil-borne diseases and weeds, provide excellent drainage, prevent soil compaction, and are much easier on your back and knees since you don't have to bend down as far.

What is the best depth for a raised garden bed?

The standard depth is **12 inches**. Most garden vegetables (lettuce, spinach, radishes) only need 6-8 inches of soil depth, but root crops (carrots, potatoes) and heavy-feeding nightshades (tomatoes, peppers) need 12-18 inches to support their extensive root networks.

Do I need to change my raised bed soil every year?

No, you do not need to replace the soil. However, vegetables deplete soil nutrients during the growing season. Every spring, add **1 to 2 inches of fresh organic compost** to the top of the bed and work it into the top few inches of soil to replenish organic matter.

All calculations are estimates. Always consult a professional contractor for accurate quotes. See our Disclaimer for details.