Greenhouse Size Calculator

Overwhelmed by choices? Not sure what will fit in your yard? You’re in the right place. This tool takes the guesswork out of choosing a greenhouse. Simply enter the dimensions of your available space, and we’ll recommend the perfect type and size for your needs, based on our years of hands-on experience.

Find Your Perfect Greenhouse

Understanding the Results: A Guide to Greenhouse Types

Our calculator gives you a great starting point, but understanding the “why” behind the recommendation is key. Here’s a breakdown of the most common greenhouse types and who they’re best for.

Mini Greenhouses

Perfect for gardeners with limited space, like a balcony, patio, or small corner of a yard. These are fantastic for starting seeds, growing herbs, and protecting a small collection of prized plants. Their compact size makes them easy to manage and affordable.

Walk-In Hobby Greenhouses

This is the most popular category for backyard gardeners. They offer enough room to stand and work inside, with space for shelving and taller plants. Many of the best portable greenhouses fall into this category, offering a great balance of size, function, and value.

Hoop House / Tunnel Greenhouses

If you have a long, narrow space and your goal is to grow in-ground rows of vegetables, a hoop house is the most efficient choice. They provide maximum coverage for the cost and are ideal for serious food production, protecting long beds of the best vegetables from the elements.

Polycarbonate Greenhouses

For the gardener seeking a permanent, long-term structure, polycarbonate kits are the gold standard. Their rigid twin-wall panels offer superior insulation, durability, and light diffusion. They are a significant investment, much like learning how to build a greenhouse at home, but they provide the best performance and longevity.

Beyond Size: Other Factors to Consider

While dimensions are critical, they’re not the only piece of the puzzle. A truly successful greenhouse experience comes from a holistic approach. As you plan, keep these key factors in mind:

  • Heating & Cooling: The larger your greenhouse, the more powerful your heating and ventilation systems need to be. A well-insulated structure will drastically reduce the running costs of the best greenhouse heaters.
  • Organization: How will you use the space? Proper planning with the best greenhouse shelving and benches is crucial to maximize your growing area and keep things tidy.
  • Your Experience Level: Don’t feel pressured to start with a massive structure. Mastering a smaller space first is one of the most important greenhouse gardening tips for beginners and will build your confidence for future expansion.
Check Price on Amazon
`; } else if (sqFt >= 25 && sqFt < 70) { recommendationHTML = `

Our Recommendation: A Walk-In Hobby Greenhouse

With ${sqFt.toFixed(1)} sq ft, you have the ideal amount of space for a versatile walk-in hobby greenhouse.

This is the sweet spot for most backyard gardeners. It gives you enough room to stand and work comfortably, install shelving, and grow taller plants like tomatoes and cucumbers without a massive investment.

Suggested Product: Walk-in Greenhouse

Quictent Heavy-Duty Walk-in Greenhouse

Check Price on Amazon
`; } else if (sqFt >= 70 && length > width * 1.8) { recommendationHTML = `

Our Recommendation: A Hoop House / Tunnel Greenhouse

Your area of ${sqFt.toFixed(1)} sq ft, with its long and narrow shape, is perfect for a highly productive hoop house.

This design maximizes growing area over long garden beds, making it incredibly efficient for serious food production. It's the go-to choice for protecting rows of crops and significantly extending your growing season.

Suggested Product: Hoop House Kit

Quictent 20'x10' Tunnel Greenhouse Kit

Check Price on Amazon
`; } else { // sqFt >= 70 and not a tunnel shape recommendationHTML = `

Our Recommendation: A Polycarbonate Greenhouse Kit

With a generous ${sqFt.toFixed(1)} sq ft, you're ready for a durable, permanent polycarbonate greenhouse.

This is the best choice for a long-term investment. The rigid twin-wall panels provide superior insulation, strength against wind and snow, and excellent light diffusion for healthier plants. This is a serious structure for the dedicated gardener.

Suggested Product: Polycarbonate Greenhouse Kit

Palram Harmony 6' x 8' Polycarbonate Greenhouse

Check Price on Amazon
`; } resultsDiv.innerHTML = recommendationHTML; resultsDiv.style.display = 'block'; });

The Ultimate Greenhouse Gear & Supplies Guide

Welcome to our curated collection of the best tools, kits, and supplies to make your greenhouse thrive. We've selected top-rated, reliable products based on our hands-on experience and extensive research to help you get the best results.

Greenhouse Kits for Beginners

Walk-in Greenhouse Kit

Quictent Heavy-Duty Walk-in Greenhouse

A spacious and sturdy option with a reinforced steel frame, perfect for serious beginners wanting ample space for a variety of plants.

Check Price on Amazon
4-Tier Mini Greenhouse

Gardman 4-Tier Mini Greenhouse

Ideal for patios, balconies, and small spaces. Excellent for starting seeds and protecting a small collection of plants without a large footprint.

Check Price on Amazon
Lean-To Greenhouse Kit

Palram Hybrid Lean-To Greenhouse

Attaches directly to your home or garage, providing easy access to utilities and excellent heat retention from the adjoining wall.

Check Price on Amazon
Cold Frame Greenhouse

Outsunny Wooden Cold Frame

A compact, ground-level option perfect for hardening off seedlings in the spring and protecting low-growing crops in the fall.

Check Price on Amazon
Pop-Up Greenhouse

EAGLE PEAK Pop-Up Greenhouse

The ultimate in convenience. This greenhouse sets up in minutes and is perfect for temporary, seasonal plant protection.

Check Price on Amazon

Climate Control Essentials

Wireless Thermo-Hygrometer

Govee Wireless Thermo-Hygrometer

Monitor your greenhouse temperature and humidity from your phone. Essential for understanding your microclimate and preventing plant stress.

Check Price on Amazon
Automatic Vent Opener

Univent Automatic Vent Opener

A must-have device that opens and closes your roof vent automatically based on temperature, preventing overheating without any electricity.

Check Price on Amazon
Oscillating Circulation Fan

Hurricane Classic Oscillating Fan

Constant air movement is key to preventing fungal diseases and strengthening plant stems. This is a durable, wall-mountable option.

Check Price on Amazon
Aluminet Shade Cloth

Be Cool Solutions Aluminet Shade Cloth

In hot climates, a shade cloth is essential to reduce peak summer temperatures and prevent sun scorch on your plants.

Check Price on Amazon
Electric Greenhouse Heater

Mr. Heater Electric Greenhouse Heater

A safe, reliable heater with a built-in thermostat to keep your greenhouse frost-free through the cold winter months.

Check Price on Amazon

Seed Starting & Propagation

Seedling Heat Mat

VIVOSUN Seedling Heat Mat

Dramatically improves germination rates, especially for heat-loving plants like tomatoes and peppers, by warming the root zone.

Check Price on Amazon
Seed Starting Trays with Humidity Dome

Bootstrap Farmer Seed Starter Trays

Durable, reusable, and heavy-duty seed trays that won't crack after one season. The included humidity dome creates a perfect germination environment.

Check Price on Amazon
LED Grow Lights

Barrina T5 Full Spectrum LED Grow Lights

Provides essential light for starting seeds indoors or supplementing light in your greenhouse on cloudy days, preventing leggy seedlings.

Check Price on Amazon
Seed Starting Potting Mix

Espoma Organic Seed Starter Mix

A fine, lightweight, and sterile mix that provides the ideal environment for delicate new roots to grow strong and healthy.

Check Price on Amazon
Soil Blocker Tool

Ladbrooke Mini 4 Soil Blocker

An eco-friendly alternative to plastic pots. This tool creates compressed blocks of soil for starting seeds, encouraging robust root growth.

Check Price on Amazon

Essential Tools & Supplies

Felco F-2 Hand Pruners

Felco F-2 Classic Manual Hand Pruner

The industry standard for a reason. A "buy it for life" tool with sharp, replaceable blades for clean cuts when pruning and harvesting.

Check Price on Amazon
Watering Wand with Thumb Control

Dramm One Touch Rain Wand

Allows you to gently water the base of your plants without disturbing the soil or wetting the foliage, which helps prevent disease.

Check Price on Amazon
3-in-1 Soil Meter

XLUX 3-in-1 Soil Moisture Meter

Takes the guesswork out of watering by measuring moisture at the root level. Also measures light and pH for a complete picture of your soil health.

Check Price on Amazon
Yellow Sticky Traps

Trapro Yellow Sticky Traps

Your first line of defense against common flying pests like fungus gnats, whiteflies, and aphids. An essential for early pest detection.

Check Price on Amazon
Jute Garden Twine

KINGLAKE Natural Jute Twine

A multi-purpose essential for tying up tomato plants, trellising cucumbers, labeling plants, and a hundred other tasks in the greenhouse.

Check Price on Amazon

Potting & Organization

Fabric Grow Bags

VIVOSUN Fabric Grow Bags (5-Pack)

Promotes healthier root systems through "air pruning." An excellent, breathable alternative to plastic pots for growing almost any vegetable.

Check Price on Amazon
Wooden Potting Bench

Best Choice Products Outdoor Potting Bench

Save your back! A dedicated workspace for potting, seeding, and organizing your tools makes your greenhouse time much more efficient and enjoyable.

Check Price on Amazon
FoxFarm Ocean Forest Potting Mix

FoxFarm Ocean Forest Potting Soil

A premium, nutrient-rich potting mix that gives your container plants the best possible start. Ready to use right out of the bag.

Check Price on Amazon
Bamboo Plant Labels

Whaline Bamboo Plant Labels

An eco-friendly way to keep your garden organized. Essential for remembering which varieties of seeds you planted where.

Check Price on Amazon
Heavy-Duty Wire Shelving Unit

Amazon Basics 4-Tier Wire Shelving

Maximize your vertical space with sturdy wire shelving. Perfect for storing supplies, curing onions, or holding trays of seedlings.

Check Price on Amazon
Scroll to Top