Download your Word document
Gambrel Roof Surface Area Calculator result sheet — free, supported by sponsors. Your download button appears in 20 seconds.
This free download is supported by sponsors — continuing in
20
Your file is generated in your browser when you choose Download — nothing is uploaded. If this calculator returns enough numeric data, the export also includes its best-fit chart alongside the readable table.
WorldCalculate result export
Gambrel Roof Surface Area Calculator — result sheet
Estimate two-sided gambrel roof surface area from building length and the two roof-slope segments.
Inputs used
Results
Visual chart
Breakdown
Calculation steps
Returned data table
Formula and methodology
Formula: upper run=half span−lower run; one-side area=length×(√(lower run²+lower rise²)+√(upper run²+upper rise²)); total=2×one-side area×(1+waste).
The model treats each side as two planar rectangles along a symmetrical gambrel cross-section. Eaves, overhangs, dormers, valleys, fascia, and panel layout are excluded unless added to the dimensions.
This result follows the calculator's declared inputs, precision, validation boundaries, and model limits.
Input contract
- Building length — minimum 1.0E-6; maximum 10000
- Half roof span — minimum 1.0E-6; maximum 1000
- Lower slope horizontal run — minimum 1.0E-6; maximum 1000
- Lower slope rise — minimum 0; maximum 1000
- Upper slope rise — minimum 0; maximum 1000
- Waste allowance (%) — minimum 0; maximum 100
Worked example
| Input | Value |
|---|---|
| Building length | 10 |
| Half roof span | 4 |
| Lower slope horizontal run | 2.5 |
| Lower slope rise | 1.5 |
| Upper slope rise | 1.2 |
| Waste allowance (%) | 10 |
Waste-adjusted two-sided area≈82.233 m² in the entered unit system.
Assumptions and limits
- The lower run is less than the half span and the roof is symmetric.
- All dimensions use one consistent length unit.
- Waste is a planning allowance and does not select shingle, panel, or membrane coverage rules.
Calculator note
Source and methodology
Use the official WorldCalculate methodology policy for the source, formula, precision, and boundary standards behind this calculator.
Planning estimate, not financial, medical, legal, or professional advice. © WorldCalculate — reuse with attribution. Built and curated by Hassan ALRowaie.
No saved result was found. Please run the calculation first, then choose Download again.