Formula used
Roof rise: rise = run × pitch rise ÷ 12.
Roof angle: angle = arctan(rise ÷ horizontal run).
Stud top: wall height + proportional gable rise.
Finished stud: stud top − bottom plate − top plates.
Gable area: rectangle area + one-half × width × rise.
The calculator interpolates every stud against the selected roof slope. Plate layers reduce each finished stud length. Openings can divide studs into upper and lower segments.
How to use this calculator
- Select one measurement unit for all dimensional entries.
- Enter wall width, wall height, and roof pitch.
- Choose framing spacing, lumber dimensions, and plate layers.
- Add vents, windows, doors, or custom openings.
- Set sheathing, stock lengths, waste, and pricing.
- Calculate, review warnings, then export the schedule.
Worked example
A 24-foot gable uses eight-foot walls and a 6:12 pitch. The ridge sits at the center, and studs use sixteen-inch spacing. The calculator finds a six-foot roof rise and fourteen-foot ridge elevation.
| Input | Example value | Purpose |
|---|---|---|
| Wall width | 24 ft | Defines the gable span |
| Wall height | 8 ft | Defines rectangular wall height |
| Roof pitch | 6:12 | Defines roof rise |
| Stud spacing | 16 in | Defines stud centerlines |
Roof pitch reference
| Pitch | Angle | Slope |
|---|---|---|
| 3:12 | 14.04° | 25% |
| 4:12 | 18.43° | 33.33% |
| 5:12 | 22.62° | 41.67% |
| 6:12 | 26.57° | 50% |
| 8:12 | 33.69° | 66.67% |
| 12:12 | 45° | 100% |
Common lumber sizes
| Nominal size | Typical actual size | Common use |
|---|---|---|
| 2 × 4 | 1.5 × 3.5 in | Standard wall framing |
| 2 × 6 | 1.5 × 5.5 in | Insulated exterior walls |
| 2 × 8 | 1.5 × 7.25 in | Headers and special framing |
Cutting and measuring guidance
Verify the actual plate stack before cutting production studs. Mark every stud from one consistent wall reference. Confirm local requirements before ordering materials or beginning work.
Use the fractional schedule as a layout aid only. Saw kerfs and field conditions can change final cuts. Test one stud before repeating matching cuts across framing.
Frequently asked questions
Does the calculator support an offset ridge?
Yes. Set the ridge position percentage anywhere inside the wall span.
Can I use metric dimensions?
Yes. Select millimeters, centimeters, or meters before entering dimensions.
How are stud lengths calculated?
Each stud intersects the roof line at its horizontal centerline.
Are plate thicknesses deducted?
Yes. Bottom and selected top plate layers reduce finished lengths.
Can openings be added?
Yes. Add windows, vents, doors, louvers, or custom rectangles.
Does it estimate king and jack studs?
Yes. Each opening accepts separate king and jack quantities.
How is sheathing estimated?
Net wall area is divided by sheet area, then waste applies.
What does the cutting plan do?
It uses a greedy layout to group pieces onto stock boards.
Can results be exported?
Yes. Use CSV, PDF, print, or copy controls.
Does the estimate replace engineered plans?
No. Structural design and code compliance require qualified review.
Why might field cuts differ?
Actual lumber, plate stacks, saw kerfs, and framing tolerances vary.
Construction estimate disclaimer
This calculator provides planning estimates, not structural approval. Bracing, headers, connections, loads, and fastening require code review. Use approved plans and qualified professionals for final construction.