Hoop House Calculator — Quickly calculate area, cover & heater size

Hoop house calculator: accurately determine surface area, material requirements, heater sizing, and cost estimates for your greenhouse project. Our mobile-friendly tool provides instant results with detailed calculations.

Input Parameters

Dimensions

m
m
m
m
m

Environment & Thermal

°C
°C
85%

Materials & Cost

$/m²
$/m
%

Structure Preview

Results

72.4 m²
Surface Area (excl. floor)
79.6 m²
Material Required (incl. 10% waste)
11 hoops
Number of Hoops
172.8 m
Total Pipe Length
3.2 kW
Heater Size Required
$428.48
Estimated Material Cost

This hoop house calculator uses standard engineering formulas to estimate your greenhouse requirements:

Surface Area Calculation

For Quonset (arched) shape:

Radius = Width / 2 Arch Length = π × Radius Roof Area = Arch Length × Length End Area = 2 × (0.5 × π × Radius²) Total Area = Roof Area + End Area

Example calculation for a 6m wide, 10m long Quonset hoop house:

Radius = 6 / 2 = 3m Arch Length = 3.1416 × 3 = 9.42m Roof Area = 9.42 × 10 = 94.2m² End Area = 2 × (0.5 × 3.1416 × 3²) = 28.27m² Total Area = 94.2 + 28.27 = 122.47m²

Material Required

Material Area = Total Area × (1 + Waste Percentage/100)

Number of Hoops

Number of Hoops = ceil(Length / Hoop Spacing) + 1

Heater Size

ΔT = Inside Temp – Outside Temp Heat Loss (W) = U-value × Area × ΔT Heater Required (W) = Heat Loss / Heater Efficiency Heater (kW) = Heater Required / 1000

Example heater calculation:

ΔT = 20°C – 5°C = 15°C Heat Loss = 2.7 W/m²K × 72.4 m² × 15°C = 2932.2 W Heater Required = 2932.2 W / 0.85 = 3449.6 W Heater Size = 3449.6 / 1000 = 3.45 kW
How to size a hoop house?

Start by determining your growing needs, then use this calculator to estimate materials and costs. Consider factors like crop type, local climate, and available space.

What U-value should I use for my greenhouse?

For single-layer polyethylene, use 4.0-5.0 W/m²K. Double-layer poly is typically 2.7 W/m²K. Polycarbonate panels range from 1.5-3.0 W/m²K depending on thickness.

What’s a typical hoop spacing for a greenhouse?

For small hobby greenhouses, 1-1.5m spacing is common. Commercial structures often use 1.5-2m spacing. Closer spacing provides more strength against snow and wind loads.

How much waste percentage should I include?

Typically 10-15% for material overlap and cutting waste. For complex shapes or inexperienced builders, consider 15-20% to ensure you have enough material.

What heater efficiency should I assume?

Modern high-efficiency heaters are 85-95% efficient. Older units may be 70-80% efficient. Electric heaters are typically 100% efficient but may have higher operating costs.

Should I include the floor in surface area calculations?

Generally no, as the floor isn’t typically covered with the same material. However, if you’re calculating heat loss through the floor, you might include it with appropriate insulation values.

How do I convert between metric and imperial units?

1 meter = 3.28084 feet, 1 m² = 10.7639 ft², °C to °F: (°C × 9/5) + 32, 1 kW = 3412.14 BTU/hr. This calculator handles conversions automatically when you switch units.

Step-by-Step Guide

  1. Select your structure shape – Choose between Quonset/arched, gable roof, or lean-to designs
  2. Enter dimensions – Width, length, height, and hoop spacing
  3. Set environmental conditions – Inside and outside temperatures for heater sizing
  4. Choose cover material – Select from common materials or enter a custom U-value
  5. Add material costs – Input prices for cover material and structural pipes
  6. Review results – Check surface area, material requirements, heater size, and costs
  7. Export your spec sheet – Download CSV or PDF for your records or to share with contractors