About Lawn & Garden Calculators

Last updated June 5, 2026

I kill fewer plants than I used to — mostly because I stopped guessing at soil volume, seed coverage, and mulch quantities. These are the yard and garden calculators I actually use each season, with the formulas in the open.

What’s on this site

Right now there are 6 calculators here: Landscape Material Calculator, Raised Bed Soil Calculator, Grass Seed Calculator, Pool Volume Calculator, Fertilizer Calculator, and Plant Spacing Calculator. Each one is a single-purpose tool that shows its formula, lists its assumptions, and runs on any device with no signup.

Why these are different

Most calculator sites hand you a number and hide the formula. Every tool here does the opposite: the exact formula, the assumptions, and a worked example are shown right on the page, so you can check the result instead of trusting it blindly. There’s no account, no paywall, and no signup.

How the math is kept honest

Each formula is shown in full and was independently re-derived and spot-checked against the calculator’s code. Reference values (typical rates, averages, rules of thumb) are labeled as approximate and are editable, so you can put in your own real numbers. These are gardening estimates, not agronomic or landscaping advice — soil, climate, and plant needs vary, so adjust to your own conditions.

Found a mistake?

I’d genuinely like to know. Email [email protected] and I’ll fix it.