Method
Slope factor = √[1 + (rise/12)²]; roof area = plan area × slope factor.
Everyday worksheet
Roofing Calculator
Estimate sloped roof area, roofing squares and waste from plan dimensions and roof pitch.
The calculation runs locally. Results include the intermediate values, unit conversions and assumptions needed to audit the answer.
Method, assumptions and practical use
How the Roofing Calculator works
Slope factor = √[1 + (rise/12)²]; roof area = plan area × slope factor. Inputs stay in this browser, and the result table exposes conversions and assumptions for independent checking.
Interpret the result
The order quantity adds a planning allowance after calculating the geometric requirement.
Check the assumptions
Field conditions, compaction, cuts, breakage, packaging and supplier units vary; verify final orders with a qualified contractor or supplier.
Local calculation
Everything runs in this browser. Inputs are not sent to an external calculator.
Rounding
Displayed values may be rounded for readability while calculations use full floating-point precision unless the tool explicitly uses exact integers.
Scope
Field conditions, compaction, cuts, breakage, packaging and supplier units vary; verify final orders with a qualified contractor or supplier.
Simple by design
Three steps to a clearer number.
Enter your details
Use realistic values in each field. You can change them anytime.
Calculate instantly
The formula runs locally, so there is no account or waiting time.
Use the result
Treat the answer as a practical estimate for your next decision.