Garden Square Foot Calculator

Q: How do I calculate garden bed square footage?

Multiply bed length by width in feet. A 4x8 ft raised bed is 32 square feet. A 10x20 ft in-ground garden is 200 square feet.

Q: How much compost do I need per square foot?

Apply 1-2 inches of compost per year over garden beds. For 1 inch of compost on 100 sq ft: 100 x 0.083 / 27 = 0.31 cubic yards (about 8 cubic feet or 4 standard bags).

What is garden square footage?

Garden square footage is the total bed area for plants, soil, and mulch. Measure length × width of each bed in feet and sum the totals. For wood-chip coverage, use the mulch calculator; for the surrounding lawn, the lawn calculator.

Getting started

How to Calculate Garden Square Footage

To calculate garden square footage, measure length × width of each bed in feet. For curved beds, divide into rectangles and triangles. Sum all bed areas for total garden square footage. Most vegetables need 1-2 sq ft per plant.

1. Measure garden beds

Measure length × width of each bed in feet. Divide curved beds into smaller shapes.

2. Calculate total area

Sum all bed areas for total garden square footage.

3. Plan plants per area

Vegetables need 1-2 sq ft per plant. Flowers vary by species.

Quick reference

Reference

1 acre = 43,560 square feet

1 square yard = 9 square feet

1 square meter = 10.764 square feet

1 square inch = 0.00064516 square feet

Material pricing

Calculate Cost of Materials

Garden soil costs $20-50 per cubic yard. Plants run $1-15 each depending on type. Multiply area by price per unit for material total.

There are 2 steps to calculate material cost:

For soil and mulch, enter price per cubic yard or per bag. For plants, enter price per plant or flat.
The Square Foot Calculator multiplies garden area by your unit price (or by depth for bulk) for material cost.

Add 10-15% extra material for replanting and bed expansion.

FAQ

Frequently Asked Questions

How do I calculate garden bed square footage?

Multiply bed length by width in feet. A 4x8 ft raised bed is 32 square feet. A 10x20 ft in-ground garden is 200 square feet.

How much soil do I need for a raised bed?

Multiply bed area (sq ft) by depth (ft), then divide by 27 for cubic yards. A 4x8 ft bed that is 12 inches deep needs: 32 x 1 / 27 = 1.19 cubic yards of soil mix.

What is square foot gardening?

Square foot gardening divides beds into 1x1 ft squares, each planted with a specific number of plants based on size. A 4x4 ft bed has 16 planting squares, maximizing space efficiency.

How many plants per square foot?

It depends on plant size: 16 small plants (radishes), 9 medium (beets), 4 large (lettuce), or 1 extra-large (tomato) per square foot. Check spacing requirements for each variety.

How much compost do I need per square foot?

Apply 1-2 inches of compost per year over garden beds. For 1 inch of compost on 100 sq ft: 100 x 0.083 / 27 = 0.31 cubic yards (about 8 cubic feet or 4 standard bags).

How big should my garden be for a family of 4?

A 200-400 sq ft garden can feed a family of 4 with fresh vegetables during growing season. Start with 100 sq ft if you are a beginner and expand as you gain experience.

REFERENCES

Garden Square Foot
Calculator — Plot Area Tool

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