For Reference Only

The calculators on Roofer Toolkit are provided for reference and estimation purposes only. Results are based on standard rafter framing geometry and published carpentry conventions. They are not a substitute for professional structural assessment, engineered drawings, or verification against your local building code.

Always double-check critical measurements before cutting lumber. Errors in rafter layout can affect the structural integrity of a roof.

Safety Warning

Building Code

Where code references appear in these calculators (such as IRC R802.7.1 for birdsmouth cuts), they are provided as general reference based on commonly adopted model codes. Your local Authority Having Jurisdiction (AHJ) may have adopted a different code edition or local amendments that change the applicable requirements.

Always verify code compliance with your local building department before starting permitted work. These tools are not a substitute for a permit application or building inspection.

Accuracy

We make every effort to ensure the math in these calculators is correct. However, we make no warranty, express or implied, regarding the accuracy, completeness, or fitness for any particular purpose of the results produced. Use the results at your own discretion and verify any critical measurement independently.

If you find an error in the math or output, please contact us so it can be corrected.

Affiliate Links

Some pages on this site may contain affiliate links to products on Amazon, Home Depot, Lowe’s, or other retailers. If you click an affiliate link and make a purchase, we may earn a commission at no additional cost to you. Affiliate relationships do not influence calculator results or tool recommendations.

No Professional Relationship

Use of this site does not create any professional, contractor, or advisory relationship between you and the operators of Roofer Toolkit. The information provided is general in nature and may not apply to your specific situation, materials, or jurisdiction.