Ventilation Calculator

Stop Guessing, Start Calculating: Precise Roof Ventilation

Streamline ventilation planning by accurately calculating needs based on roof complexity and code requirements, eliminating guesswork and ensuring projects stay compliant and on schedule.

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Why Accurate Ventilation Calculations Matter

Meet all relevant building codes and regulations with accurate ventilation calculations

Optimize airflow and improve energy efficiency by ensuring proper ventilation

Minimize the risk of moisture-related issues like mold, mildew, and wood rot, protecting the long-term structural integrity of the home

Generate supporting reports and documentation on ventilation calculations for insurance adjusters, homeowners, and other stakeholders

Building code violations, resulting in costly fines and project delays

Moisture buildup resulting to mold growth, wood rot, and structural damage

Strain HVAC systems, leading to higher energy consumption and increased utility costs

The formation of ice dams on the roof during winter months

Effortless input

Easily input roof dimensions, pitch, and ventilation details, streamlining the calculation process and saving valuable time.

Code compliance

Ensures your projects meet all relevant building codes and regulations, minimizing the risk of violations and costly fines.

Detailed reports

Generate professional documentation, including precise calculations, clear diagrams, and code references to support your projects.

Clear communication

Accurate and easily understandable ventilation data facilitates a smoother and faster claims process for adjusters, insurers, and contractors.

Step 1

Enter project information

Step 1 (1)

STEP 2

Click “Calculate”

Step 2 (1)

STEP 3

Check Roof Plan and “Create Report”

Step 3-3

STEP 4

Get your report!

Step 4-2

Your Top Questions Answered

Ventilation Calculator:

Q: What does the OneClick Code Ice and Water Shield Calculator do?
The Ventilation Calculator helps roofing professionals determine how much attic ventilation is needed to meet code and protect a home. By entering your attic square footage, roof slope, and vent type, the tool calculates the proper intake and exhaust ventilation for balanced airflow. This helps contractors avoid calculation errors, speed up estimates, and ensure every project meets code requirements without guesswork.

Q: What information do I need to use OneClick Code’s Ventilation Calculator?
To use the calculator, you’ll need your roof size (in square feet), your predominant roof pitch (expressed as rise over 12 inches of run, such as 6/12), and any existing roof or attic vents (optional). If you’re including existing vents, you’ll only need to enter details for the types currently in place:

Turtle vents – total quantity (EA)
Ridge vents – total length in linear feet (LF)
Power vents – total quantity (EA)
Turbine vents – total quantity (EA)
Gable vents – total quantity (EA)

The calculator uses these inputs to determine the balanced intake and exhaust ventilation needed for your project and provides the totals so you can meet code requirements with confidence.

Q: How does the Ventilation Calculator make estimating and planning easier?
OneClick Code’s Ventilation Calculator eliminates the need for manual math by using your roof details to calculate balanced intake and exhaust ventilation. It ensures accurate numbers the first time, helping you build faster estimates, order the right materials, and avoid costly errors, delays, or inspection failures.

Q: How can I be sure my attic ventilation meets local code requirements?
Ventilation requirements vary by jurisdiction, roof design, and whether the 1/150 or 1/300 rule applies. The calculator handles the math, and OneClick Code’s platform gives you verified, jurisdiction-specific roofing codes tied to your address, so you can confirm compliance, prevent costly issues like attic moisture, and meet manufacturer standards for warranty protection.

Q: When building a cost estimate for a roof project, what tool can I use to determine how many roof vents I need?
OneClick Code’s Ventilation Calculator does the math for you. By entering your roof dimensions, the tool instantly calculates the intake and exhaust ventilation needed for your project. This makes it easy to build accurate cost estimates and order the right materials without guesswork.