About GardenCalc

GardenCalc is a free collection of garden calculators designed to help home gardeners, landscapers, and horticulture enthusiasts plan and manage their gardens with confidence. From working out how much compost to fill a raised bed to figuring out the right fertilizer rate for your lawn, our tools give you instant, accurate numbers without requiring a spreadsheet or a degree in agronomy.

Our Mission

We believe every gardener deserves access to accurate, easy-to-use calculation tools without paywalls or sign-up requirements. Gardening decisions — how much soil to buy, how far apart to space seedlings, how much fertilizer to apply — involve real math that can make or break a growing season. GardenCalc exists to make that math effortless. All our calculators run entirely in your browser, so results are instant and your data stays on your device.

What We Offer

• Soil & Bed Calculators: Calculate soil volume for raised beds, planters, and garden beds in cubic feet or cubic yards, so you order exactly the right amount of fill.
• Plant Spacing & Seed Calculators: Work out how many plants or seeds you need for a given area based on recommended spacing — no more guessing at the garden center.
• Fertilizer & NPK Calculators: Calculate application rates and blend custom NPK ratios for your specific crop needs and soil test results.
• Lawn Care Calculators: Estimate overseeding rates, soil amendment quantities, and watering schedules for lawns of any size.

How the Tools Work

Each GardenCalc tool is built with plain HTML, CSS, and JavaScript. When you enter your dimensions or rates and press calculate, the math runs entirely inside your browser — no data is sent to any server. This means the tools work offline after the initial page load, which is handy when you're in the garden with limited connectivity.

Who Uses GardenCalc

Our users range from first-time container gardeners trying to fill a single raised bed to professional landscapers managing large commercial plantings. Homeschool educators use our tools to teach practical math. Market gardeners use our seed quantity calculators to plan crop rotations. Whatever your gardening scale, GardenCalc has a tool for you.

Accuracy

Our formulas are based on established horticultural guidelines from university extension services and standard garden math. Results are estimates and should be verified with soil tests and local expert advice for critical applications such as fertilizer programs on food crops or large landscaping projects.