Free Garden Tools

Garden Tools & Calculators

Free, professional-grade calculators for plant spacing, soil volume, mulch coverage, and more. No sign-up required.

Hardiness Zone Finder

Enter your zip code or postal code to find your USDA or Canadian hardiness zone. See temperature ranges and discover plants that thrive in your area.

Find Your Zone

Plant Spacing Calculator

Calculate how many plants you need for any garden bed, hedgerow, or bulb planting. Supports square, triangular, and offset grid patterns with a live visual preview of your layout.

Calculate Spacing

All calculators

Companion Planting Planner Soil & Mulch Calculator Fertilizer Calculator Grass Seed Calculator Sod Calculator Tree Protection Zone Calculator Tree Soil Volume Calculator Tree Risk Assessment Checklist Tree Service Cost Estimator Raised Bed Lumber Calculator Hardscapes Calculator

Why Gardeners Choose Our Calculators

Built by gardeners, for gardeners. Professional results without the complexity.

100% Free

No sign-up, no paywall. Every calculator is free forever.

Mobile Friendly

Works perfectly on phones, tablets, and desktops.

No Sign-Up Needed

Every calculator works instantly. An account is only for saving plans.

Professionally Accurate

Formulas vetted against industry standards and horticultural guides.

Plan Beyond the Calculators

Your saved plans connect to the rest of Plant Reference — design garden layouts in Workspaces and keep up with seasonal care using Maintenance Plans.

Garden Workspaces

Design garden layouts on a visual canvas — arrange plants, sketch beds, and send calculator plans straight to a workspace.

Open Workspaces

Maintenance Plans

Turn your garden into a seasonal care schedule — pruning, feeding, mulching, and frost alerts for every plant you grow.

Build My Plan

About Plant Reference