Garden Calculators

Find the Right Garden Calculator for Your Project

Garden planning goes wrong when the numbers are off — not enough soil for a raised bed, the wrong planting date for your last frost, or an irrigation system that can't keep up with your garden's water needs. These tools give you the right numbers before you buy materials or put seeds in the ground.

Vegetable Garden Planning and Planting Schedules

Timing is everything in the vegetable garden. The Garden Planting Calendar generates a complete sow and transplant schedule based on your last frost date — it tells you exactly when to start seeds indoors and when it's safe to move plants outside. Not sure of your zone? Use the Frost Date Calculator to look up last spring frost and first fall frost dates for your location. The Seed Starting Calculator counts back from your transplant date to tell you when to germinate each crop. Once you're planting, the Plant Spacing Calculator tells you how many plants fit in a given bed based on the variety's spacing requirements, and Companion Planting shows which crops grow well together and which inhibit each other.

Soil, Compost, and Raised Beds

Raised beds fail when they're filled with the wrong mix — too much native soil compacts, too much peat dries out. The Raised Bed Calculator calculates cubic footage for any bed dimensions, and the Container Garden Mix Calculator shows the right ratios of compost, topsoil, and perlite or vermiculite for container growing. Need to top-dress or refresh existing beds? The Soil Calculator converts area and depth to cubic yards or bags. For composting, the Compost Ratio Calculator balances carbon-to-nitrogen ratios across your greens and browns. Thinking about lawn renovation? The Lawn Fertilizer Schedule creates a seasonal feeding plan, and the Lawn Seed Calculator estimates seed quantities for overseeding or new establishment.

Irrigation and Water Management

Watering is the highest source of garden waste — both water wasted and plants lost to inconsistency. The Irrigation Calculator sizes a system to deliver adequate water across your garden area based on plant water requirements and soil type. For drip irrigation specifically, the Drip Tape Calculator calculates emitter spacing and flow rates for raised bed rows. Collecting rainwater? The Rain Barrel Calculator estimates storage capacity needs from your roof area and average rainfall, and the Rainwater Harvesting Calculator shows how much annual collection you can expect from your roof. Growing in a greenhouse? The Greenhouse Heating Calculator sizes a heater based on structure dimensions and your winter temperature differential, and the Grow Light Calculator matches fixture wattage and coverage to your growing area.

Backyard Chickens

Keeping chickens requires more planning than most people expect. Space requirements, feed needs, and egg production all scale with flock size. The Chicken Coop Size Calculator determines minimum floor space per bird for different breeds and housing types. The Chicken Feed Calculator estimates daily and monthly feed quantities based on flock size and hen stage. Curious about what your flock will actually produce? The Egg Production Estimator forecasts weekly eggs based on breed, hen age, and season.

Getting Started Each Season

Every garden season starts the same way: look up your frost dates, then build your planting calendar from that anchor date. The Frost Date Calculator and Garden Planting Calendar work together as a natural first step before anything else. Next, check your soil situation — if you're starting new beds, the Raised Bed Calculator and Soil Calculator help you plan materials before your delivery or store trip. Established gardeners refreshing beds should run the Mulch Calculator to estimate top-dressing needs. Mid-season, irrigation questions dominate — the Irrigation Calculator and Drip Tape Calculator help tune watering as summer heat arrives. The Companion Planting tool is worth consulting when adding new crops, since some combinations (tomatoes with basil, carrots with onions) are mutually beneficial, while others (fennel with most vegetables) can inhibit growth. All tools support metric and imperial inputs and are mobile-friendly for use in the garden. Since every calculation runs in your browser, you can use them in the yard without worrying about cellular signal. The planting calendar and seed starting tools are particularly useful on mobile — pull them up while you're in the garden and reference sowing dates without going back inside to look things up. Bookmark the tools you return to most often for quick seasonal access. For new gardeners, the Frost Date Calculator and Garden Planting Calendar are the natural starting point — everything else builds from knowing those anchor dates. For experienced gardeners expanding or troubleshooting, the soil, irrigation, and fertilizer tools are the most frequently used for scaling decisions and diagnosing what's going wrong mid-season. Most of these tools also work well for small-scale hobby gardens and large market gardens alike — input your actual dimensions and quantities rather than using defaults.