Roof Rise & Height
RISE · RAFTERYour Results
RISE · HEIGHT · RAFTERRise is measured from the eave (wall top) up to the ridge.
Rise · Ridge Height · Rafter
Roof Rise & Height Calculator
Work out the rise of a roof and its ridge height from the pitch and the building span. Enter your pitch and width to get the rise above the eave, the rafter length per side, the pitch angle and — if you add a wall height — the total peak height.
- Rise = (span ÷ 2) × (pitch ÷ 12)
- Also returns rafter length and pitch angle
- Add wall height for the total peak height
- Feet or metres — your choice
How to Calculate Roof Rise and Height
The run of a symmetrical gable roof is half the building span. The rise is the run multiplied by the pitch expressed as a fraction of 12:
rise = (span ÷ 2) × (pitch ÷ 12)
For a 30 ft span at a 6:12 pitch, the run is 15 ft and the rise is 15 × (6 ÷ 12) = 7.5 ft. The rafter length per side is √(run² + rise²) = 16.77 ft. Add your wall height to the rise for the total height to the ridge.
Need the pitch itself first? Use the main roof pitch calculator, or convert the angle on the pitch-to-degrees page.
Full Roof Pitch Calculator
Prefer to start from rise and run instead? The complete pitch calculator with its live diagram is below.
Roof Pitch Calculator
LIVE RESULTStandard run = 12 in
Your Results
PITCH · ANGLE · SLOPEConventional / standard slope
Drag the orange apex to change both rise and run, or the blue handles to adjust one at a time. The boxes above stay in sync.
Frequently Asked Questions
How do I calculate the rise of a roof?
Multiply half the building span by the pitch divided by 12. For a 30 foot span at 6:12, the rise is 15 times 6 divided by 12, which is 7.5 feet.
What is roof ridge height?
Ridge height is the roof rise plus the height of the walls the roof sits on, measured from the eave line up to the peak.
How do I find rafter length from pitch and span?
Rafter length per side is the square root of run squared plus rise squared, where run is half the span.
More Roof Pitch Calculators
Purpose-built tools for every roofing measurement — pick the one that matches your job.
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Slope-factor calculator & full multiplier chart
Roof Pitch to Degrees
Convert pitch to degrees and back, with a chart
Roof Pitch Chart
Every pitch in degrees, slope % and multiplier
Lean-To / Shed Roof Pitch
Single-slope pitch and minimum fall
Flat Roof Fall
Fall in mm per metre, ratio and angle
Roof Pitch Calculator
The main rise-over-run tool with live diagram