Tools/ Calculators/ Manual J Load Calculator
ASHRAE-based · ACCA MJ8ae method

Free Manual J Load Calculator

Full residential load calculation + Manual D duct sizing + customer-ready PDF report. ASHRAE-based physics. Implements the ACCA Manual J 8 Abridged Edition method. Built by working contractors. Hosted on its own subdomain.

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Open the full Manual J calculator

The calculator runs on its own subdomain at loadcalc.launchmyhvac.com. Whole-house block load, per-room distribution, AED check, latent load, equipment sizing, and customer-ready PDF. Free.

Open the calculator →
No signup · No per-report fee · Opens in a new tab

What's in it

  • Whole-house block load
  • Per-room distribution
  • AED check (over-glazed west)
  • Latent load for humid climates
  • Manual D duct sizing
  • Customer-ready PDF report

vs the legacy tools

  • CoolCalc: ~$2.67/report
  • Wrightsoft: $2,400–4,800/yr
  • Carrier HAP: ~$1,500/yr
  • This: free, forever

Honest scope

Design-assist for residential and small-commercial. Not ACCA-certified — cross-check against an ACCA-approved tool for code-strict permits.

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