# What is Manual J and ACCA-approved load-calc software?

Plain-language primer on ACCA Manual J residential load calculations and why contractors check ACCA's approved software list. No invented stats.

- Canonical: https://www.loadcalcstack.com/guides/what-is-manual-j-acca-approved-software
- Category: standards
- Updated: 2026-09-15
- Author: LoadCalcStack editorial team

Manual J is ACCA's residential heating and cooling load calculation standard. LoadCalcStack covers software used to run those calculations for HVAC contractors. This site does not rank a winner.

> Verified fact: ACCA's approved software page (retrieved 2026-09-15) states that only ACCA-approved software complies with ACCA design standards and meets building code requirements that call for those standards, and that software not listed on that page is not ACCA-approved.

> Verified fact: The same ACCA page lists full residential load calculation products (including Wrightsoft Right-J8, Elite RHVAC, Cool Calc Manual J, and Conduit Tech) and separate Manual J block-load-only and Manual D duct design sections. Manual J®, Manual D®, and Manual N® are identified there as federally registered trademarks of ACCA.

> Editorial judgment: For career-changers and new HVAC owners, start with ACCA's live approved list, then compare published vendor pricing and workflow fit. Do not treat a marketing badge alone as proof of current approval.

## What Manual J is (and is not)

Manual J estimates how much heating and cooling a home needs so equipment can be sized appropriately. Related ACCA manuals often discussed with load software include Manual S (equipment selection) and Manual D (duct design). LoadCalcStack is a software directory brand; Manual J is ACCA's standard, not our product name.

## Why "ACCA-approved software" matters

Many jurisdictions and programs expect Manual J procedures. ACCA publishes an approved software list so contractors and code officials can check which products ACCA has recognized. Always verify the live list at [ACCA approved software](https://www.acca.org/standards/approved-software) rather than relying only on a directory page.

## How LoadCalcStack uses this

We link the ACCA list as authority, cite retrieval dates on vendor prices, and note when a vendor does not publish a price — you request a quote instead.

## Related pages

- [Directory](/directory)
- [Cool Calc vs Wrightsoft](/compare/cool-calc-vs-wrightsoft)
- [Cool Calc vs Elite Software (Rhvac)](/compare/cool-calc-vs-elite-software)
- [Wrightsoft vs Elite Software (Rhvac)](/compare/wrightsoft-vs-elite-software)
- Vendor profiles: Cool Calc, Wrightsoft, Conduit Tech, Elite Software (Rhvac)