Certified Manual J Load Calculations — fast, accurate, permit-ready.
Upload your plans and get a same-day quote from a named, US-based, ACCA-certified designer. We handle Manual J, S, D, T, energy calculations, and permitting documents for residential and light commercial projects across the US, Canada, and Mexico.
500+
Projects delivered this year
25+
Years of HVAC design experience
29
States where Manual J is required
30 min
Average response time
Free DIY calculator vs. LoadCalcs
Free calculators are great for sketching. They are not permit-ready and they are not reviewed by a credentialed designer. We are both.
Free DIY tools
- Generic assumptions, no plan review
- Not signed or stamped
- Rejected by many AHJs for permits
- No accountability if numbers are wrong
- You do the data entry and the QA
LoadCalcs
- Reviewed plan-by-plan by an ACCA-certified designer
- Permit-ready reports accepted in 29+ states
- Same-day quote, 30-minute response window
- Named designer sees your project through to permit
- Revisions included if the AHJ pushes back
Three steps to a permit-ready report
Upload your plans
PDF, DWG, or images. Tell us the project type and your state — that's it.
Same-day quote
A real designer reviews your project and sends a fixed quote within hours.
Permit-ready report
Receive a stamped, ACCA-compliant Manual J (and S/D/T if needed) ready to submit.
Trusted by HVAC contractors and homeowners
"Quote in under an hour, report in two days, accepted by our county on the first submittal. That's it — that's the review."
HVAC contractor, Tampa FL
"Scott walked through the assumptions on a phone call before the report went out. Best $XXX I've spent on a project all year."
General contractor, Lexington KY
"We use LoadCalcs as our default for any new-construction Manual J. Zero permit kickbacks in 18 months."
Design-build firm, Phoenix AZ
Get a same-day quote on your load calculation.
Upload your plans, get a quote within hours, and receive a permit-ready report from a named, ACCA-certified designer.