Free Manual J Calculator for Fast, Accurate Load Sizing
Try Load Calc Guru’s free Manual J tool to generate professional load calculations and permit-ready data for HVAC projects.
Create your first load calculation and discover a faster path to permit-ready HVAC reports.
Load Calc Guru
Contractor-ready permit workflow
Standardize every load calculation and permit packet with a single workflow that keeps your team moving forward, reduces rework, and makes plan review faster.
Free to start
Professional outputs
Easy upgrade path
What contractors love
Speed, accuracy, and permit-ready outputs that help HVAC teams win approvals and close jobs faster.
No Cost, No Risk
Start with a free Manual J calculator built for HVAC contractors and see how fast you can produce accurate load results.
Professional Outputs
Generate clear load summaries and sizing recommendations that support permit applications and inspector review.
Speed Through Calculations
Complete your Manual J inputs quickly with guided fields and automated heat gain/loss logic.
Improve Permit Confidence
Even the free version delivers the essential deliverables contractors need for cleaner permit submissions.
Easy Upgrade Path
Start free and scale into full permit-ready reporting software when you’re ready for more advanced features.
How it works
A simple 3-step process to move from initial load inputs to permit-ready documentation.
Enter project details
Capture rooms, materials, and equipment in a guided contractor workflow.
Review accurate loads
Compare load results, equipment sizing, and permit-ready summaries at a glance.
Export deliverables
Download clean load reports and job-ready outputs for your HVAC permit packet.