Calculate ridge height, rafter length, and pitch for any roof truss type
What is Truss Height?
Truss height (or ridge height) is the vertical distance from the top of the wall plate to the peak of the roof. It's determined by the roof pitch (slope) and the building width. This calculator helps you find the exact ridge height, rafter length, and heel height for your roof truss design.
Building Dimensions
Roof Pitch
/12
Scissor Truss Options
Lower slope than outer
Attic Truss Options
Gambrel Truss Options
/12
/12
% from edge
Truss Height Results
Ridge Height
8.00
ft
Total Building Height
16.00
ft
Rafter Length
14.42
ft
Roof Slope Angle
33.7
degrees
Calculation Breakdown
Building Width:24 ft
Half Width (Run):12 ft
Pitch:8/12
Rise per foot of run:0.667 ft
Total Rise:8.00 ft
Ridge Height (above wall):8.00 ft
Rafter Slope Factor:1.202
/\
/ \
/ \
/ \
/ \
/ \
/____________\
Roof Pitch Reference Guide
3/12 - Very low slope (minimal)
4/12 - Low slope (easy walkability)
6/12 - Standard pitch (most common)
8/12 - Steep pitch (snow shedding)
10/12 - Very steep (dramatic look)
12/12 - 45° angle (maximum drama)
Why Getting Truss Height Right Matters
I've seen too many framing projects go sideways because someone miscalculated the ridge height. A roof that's too low feels cramped and can cause drainage issues. A roof that's too high adds unnecessary material costs and can look out of proportion with the rest of the house. That's exactly why I built this calculator - to help builders, architects, and DIYers get their truss dimensions right the first time.
Whether you're designing a new home, adding a garage, or planning a shed, knowing your exact ridge height, rafter length, and roof pitch changes everything. This calculator handles common trusses, scissor trusses for vaulted ceilings, attic trusses for bonus rooms, and gambrel trusses for barns and sheds.
How to Use This Truss Height Calculator
First, select your truss type: Common Truss for standard roofs, Scissor Truss for vaulted ceilings, Attic Truss for storage or living space, or Gambrel Truss for barn-style roofs. Enter your building width and wall height, then set your roof pitch using the preset buttons or custom input. Choose between feet/inches or meters. Click calculate to see your ridge height, total building height, rafter length, and slope angle instantly.
Pro Tips from Professional Framers
Add overhang: Ridge height calculations don't include overhangs - add 12-24 inches for eaves.
Check local codes: Minimum roof pitch varies by region and snow load requirements.
Order extra: Add 10-15% to rafter lengths for waste and cuts.
Verify with engineer: Truss designs require engineering for load calculations.
IMPORTANT DISCLAIMER: This calculator provides estimates only. Actual truss design requires professional engineering to account for snow loads, wind loads, seismic activity, and local building codes. Always consult with a structural engineer before ordering or installing trusses.
The most common roof pitch is 6/12, meaning the roof rises 6 inches for every 12 inches of horizontal run. This provides good water drainage, walkability, and aesthetic appeal.
How high should my ridge be?
Ridge height depends on building width and desired pitch. Multiply half the building width by the pitch ratio (pitch ÷ 12). For a 24ft wide building with 8/12 pitch, ridge height is 8ft above the wall plate.
What is a scissor truss?
A scissor truss has a sloping bottom chord that creates a vaulted ceiling inside. The pitch difference between top and bottom chords determines how dramatic the vaulted effect is.
What is the minimum roof pitch for shingles?
Asphalt shingles require a minimum pitch of 2/12 (2 inches rise per foot). For pitches below 4/12, special low-slope installation methods are recommended to prevent water infiltration.