About GardenCalc

GardenCalc is a free collection of garden and homestead calculators built for one purpose: helping gardeners make better decisions with simple math. Instead of guessing how much compost your pile needs, how many bags of soil a raised bed requires, or how much fertilizer your lawn can handle, you get a clear answer in seconds.

How our calculators work

Every calculator on this site is based on standard horticultural math and widely accepted gardening guidelines — the 25–30:1 carbon-to-nitrogen ratio recommended for composting, straightforward volume calculations for beds and mulch, the Mel's Mix recipe popularized by square-foot gardening, and nitrogen-based fertilizer dosing used by lawn care professionals. We combine these rules with your inputs (dimensions, materials, fertilizer analysis and more) to produce practical recommendations.

Who it's for

Beginners setting up their first raised bed or compost bin, and experienced gardeners double-checking their numbers before buying materials in bulk. If you've ever stood in a garden center wondering "how many bags is that?" or "will this pile ever heat up?", these tools are for you.

Important disclaimer

Calculator results are estimates, not professional agronomic advice. Every garden is different — soil type, climate, material quality and maintenance habits all affect real-world outcomes. Always observe your plants and soil, and adjust as needed. When in doubt, start conservatively and consult your local cooperative extension service for region-specific guidance.

Free forever

GardenCalc is free to use, supported by advertising. We don't require accounts and we don't sell your data — see our Privacy Policy for details.