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Mulch Calculator

Cubic yards and bags of mulch from bed area and depth (typically 2–3 inches).

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Soil Calculator

Topsoil or garden soil volume for beds and fill — cubic yards and bags.

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Compost Calculator

How much compost to amend beds or top-dress (usually 1–3 inches).

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Raised Bed Soil Calculator

Soil volume for one or more raised beds, with topsoil/compost mix split.

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Fertilizer Calculator

Convert N-P-K bag analysis and target nitrogen rate into pounds of product for your area.

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Seed Calculator

Seed quantity from area and rate per 1,000 sq ft (from the packet).

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Plant Spacing Calculator

How many plants fit in a bed at a given center-to-center spacing.

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Garden Watering Calculator

Gallons (and liters) to apply a target number of inches over your beds.

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Gravel Calculator

Cubic yards of gravel or crushed stone for paths, driveways and bases.

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Paver Calculator

Number of pavers plus gravel base and bedding sand volumes.

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Edging Calculator

Linear feet of landscape edging for rectangular or circular beds.

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Irrigation Calculator

Runtime and volume to deliver a target depth given precipitation rate or flow.

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Retaining Wall Calculator

Block count and approximate drainage gravel for a simple gravity wall face.

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Landscape Mulch (bulk)

Same volume math as the garden mulch tool — use the Gardening tab Mulch Calculator for beds and tree rings.

For paths and large landscape beds, use 3–4" depth and the Mulch Calculator on the Gardening tab. Add 10% waste for uneven ground.

How to calculate mulch, soil and gravel

Bulk materials are sold by the cubic yard (27 cubic feet). The core formula is:

Cubic yards = Area (ft²) × Depth (inches) ÷ 324

Or: Area × (Depth ÷ 12) ÷ 27. Add 5–10% for waste and settling. One cubic yard covers about 108 ft² at 3 inches deep.

Raised beds

Use inside length × width × soil depth. A common mix is roughly 60% topsoil and 40% compost. Soil settles after the first waterings — order a little extra.

Fertilizer

Product needed (lb) = (Area ÷ 1,000) × (lb N per 1,000 ft²) ÷ (N% ÷ 100). Always prefer a soil test when possible.

Pavers & walls

Count tiles from area and unit size (include joints). Plan a compacted gravel base and thin sand bedding. Tall retaining walls may require engineering and permits.

Garden & landscape calculator FAQ

How much mulch do I need?

Use the mulch calculator: multiply bed area (ft²) by depth in inches, then divide by 324 for cubic yards. A typical new bed needs about 3 inches of mulch; refreshing often needs 2 inches. Order 10% extra for settling.

How many cubic yards of soil for a raised bed?

The raised bed soil calculator uses inside length × width × fill depth. A 4×8 ft bed at 12 inches holds about 32 ft³ (~1.2 yd³) before waste. Mix roughly 60% topsoil with 40% compost unless your soil test says otherwise.

How do I calculate fertilizer amount?

With the fertilizer calculator, take the recommended pounds of nitrogen per 1,000 ft², divide by the nitrogen percent on the bag (as a decimal), then scale to your square footage. Example: 1 lb N/1,000 ft² with a 10-10-10 product needs 10 lb of product per 1,000 ft².

How much gravel for a path or patio base?

The gravel calculator and paver calculator convert area and depth to cubic yards. Path gravel is often 3–4 inches; paver bases are often 4–6 inches of compacted aggregate plus about 1 inch of bedding sand.

How many pavers do I need?

Divide the patio area by the area of one paver including joints, then add 5–10% waste for cuts. Our paver tool also estimates base gravel and sand so you can order materials together.

How long should I run irrigation?

Runtime (minutes) ≈ (target inches ÷ precipitation rate in/hr) × 60. The irrigation calculator also shows total gallons. Measure your system’s rate with catch cans for best accuracy.

All free YardCalc calculators

Every tool below is free, runs in your browser, and supports feet or metric where it matters: