About Contact
Tools
1 Rep Max Calculator — Estimate Your 1RM From Any Set401(k) CalculatorAge Calculator — Your Exact Age in Years, Months & DaysAmortization CalculatorAsphalt CalculatorAsphalt Driveway Cost CalculatorAuto Loan CalculatorBarcode GeneratorBase64 EncoderBd Ft CalculatorBench Press Max Calculator — Estimate Your Bench 1RMBMR Calculator — Estimate Your Basal Metabolic RateBoard Foot CalculatorBrick CalculatorCalorie Deficit Calculator — Daily Target and TimelineCD Calculator (Certificate of Deposit)Cement CalculatorCircle Area Calculator — Area, Radius, Diameter, CircumferenceColor Palette GeneratorCompound Interest CalculatorConcrete Bag CalculatorConcrete Block CalculatorConcrete CalculatorConcrete Calculator with CostConcrete Footing CalculatorConcrete Mix CalculatorConcrete Pad CalculatorConcrete Price CalculatorConcrete Slab CalculatorConcrete Slab Cost CalculatorConcrete Volume CalculatorConcrete Weight CalculatorConcrete Yard CalculatorConduit Fill CalculatorCrushed Stone CalculatorDirt CalculatorDrywall CalculatorDue Date Calculator — Estimate Your Baby's Due DateFantasy Name GeneratorFavicon GeneratorFence CalculatorFill Dirt CalculatorFinal Exam Calculator — What Grade Do I Need on the Final?Fraction Calculator — Add, Subtract, Multiply, DivideFree Citation Generator (APA, MLA, Chicago, Harvard)GPA Calculator — Unweighted and Weighted, with Cumulative GPAGravel CalculatorHEIC to JPG ConverterHELOC CalculatorInsulation CalculatorLandscape Rock CalculatorMacro Calculator — Daily Protein, Carbs, and FatMean Calculator — Average of a List of NumbersMedian Calculator — Middle Value of a List of NumbersMeme GeneratorMetal Roof CalculatorMinute to Decimal ConverterMorse Code ConverterMortgage Payoff CalculatorMulch CalculatorOvulation Calculator — Find Your Fertile WindowPaver Base CalculatorPaver CalculatorPaver Sand CalculatorPea Gravel CalculatorPeptide CalculatorPercentage Calculator — Solve Any Percent QuestionPNG to PDF ConverterPuppy Weight CalculatorPythagorean Theorem Calculator — Solve Any Right TriangleQuadratic Formula Calculator — Roots, Vertex, Factored FormQuikrete Concrete CalculatorRaised Bed Soil CalculatorRandom Name GeneratorRiver Rock CalculatorRock CalculatorRoof Cost CalculatorRoof Pitch CalculatorRoof Shingle CalculatorRoof Slope CalculatorRoof Truss CalculatorRubik's Cube Solver — Solve Any Scrambled 3×3 CubeSakrete Concrete CalculatorSales Tax CalculatorSand CalculatorScrap Silver CalculatorSignature GeneratorSleep Calculator — Best Bedtimes & Wake Times by Sleep CycleSlope Calculator — Slope, Equation, Angle, GradeSnow Day CalculatorSod CalculatorSoil CalculatorSonotube Concrete CalculatorSquare Footage Calculator — Room and Floor AreaSquat Max Calculator — Estimate Your Squat 1RMStandard Deviation Calculator — Sample and PopulationStone CalculatorTDEE Calculator — Total Daily Energy ExpenditureTier List MakerTile CalculatorTime Calculator for WorkTop Soil CalculatorTopsoil CalculatorTriangle Calculator — Solve Any Triangle From 3 InputsUPC GeneratorUsername GeneratorVolume Calculator — 8 Shapes With Unit ConversionWebP to JPG ConverterWebP to PNG ConverterWordle Solver — Best Next Guess for Today's Puzzle
← All tools

Roof Pitch Calculator

Convert rise and run into the four standard pitch formats.

Pitch from rise / run
Optional — footprint area

What is roof pitch calculator?

Roof pitch describes how steep a roof is. The standard residential convention is rise-in-12: a 6:12 pitch climbs 6 inches vertically for every 12 inches of horizontal run. That ratio also has three other useful forms — degrees of slope, percent grade, and the slope factor that multiplies footprint area into actual roof surface area.

This calculator takes rise and run in any matching unit and returns all four formats at once. Add an optional footprint length and width to see the roof’s actual surface area, which is what you need for ordering shingles, metal panels, or membrane material.

The math is plain right-triangle trigonometry: a 6:12 pitch is 26.57°, 50% grade, and a slope factor of ~1.118. Steeper pitches multiply your shingle order surprisingly fast — a 12:12 (45°, 100%) needs over 40% more roofing material than a flat reference, even with the same footprint.

When to use a roof pitch calculator

  • Identifying pitch from existing measurements — Measure a stair-step on the existing roof or attic rafter, then convert to all four formats for ordering matching shingles or trusses.
  • Planning new construction — Decide between a 4:12 and an 8:12 pitch for a new addition; see how each translates into degrees and slope factor.
  • Code and warranty checks — Confirm a roof meets the minimum pitch requirements for a specific shingle, metal panel, or membrane product.

How to use the Roof Pitch Calculator

  1. Measure rise and run — Run is horizontal distance, rise is vertical. The conventional reference run is 12 inches, but any equal-unit pair works.
  2. Read all four pitch formats — The result shows pitch as X:12, in degrees, as a percent grade, and as a slope factor (the multiplier from footprint to roof surface area).
  3. (Optional) compute roof area — Fill in the footprint length and width to see the actual roof surface area for that pitch.

Worked examples

Common residential 6:12

Input:  Rise=6 in, Run=12 in
Output: 6.00:12 — 26.57° — 50.0% — slope factor 1.118

Low-slope 2:12

Input:  Rise=2 in, Run=12 in
Output: 2.00:12 — 9.46° — 16.7% — slope factor 1.014

Steep 12:12 cathedral

Input:  Rise=12 in, Run=12 in
Output: 12.00:12 — 45.00° — 100.0% — slope factor 1.414

Frequently asked questions

What's the difference between roof pitch and roof slope?
They're synonyms in residential construction. Pitch is usually expressed as rise-in-12 (e.g., 6:12). Slope is more often expressed in degrees or percent. The math is identical.
What's a 'slope factor'?
The slope factor is √(rise² + run²) / run — the multiplier that converts horizontal footprint area into the actual roof surface area. A 6:12 pitch has a slope factor of ~1.118, meaning a 2,000 sq ft footprint has ~2,236 sq ft of roof surface.
What's the minimum pitch for asphalt shingles?
Most manufacturers spec a minimum 2:12 for asphalt shingles, with special underlayment requirements below 4:12. Always check the specific product's warranty.
How do I convert pitch to degrees?
Degrees = atan(rise / run) × 180/π. A 6:12 pitch is atan(6/12) ≈ 26.57°.
What's considered a 'steep' roof?
Anything above 9:12 (about 37°) is usually considered steep-slope and requires fall protection during work. 12:12 (45°) is a common cathedral or A-frame pitch.
Why does my pitch reading from the attic differ from the soffit?
Old framing settles unevenly and rafters can bow. Measure pitch at multiple points along the rafter and average them, or use the steepest reading for material orders.
Can I use any units for rise and run?
Yes — as long as they match. Inches and inches, millimeters and millimeters, even feet and feet. The output normalizes to rise-in-12 either way.

Roof Slope Calculator

Convert roof slope between degrees, percent, and rise-in-12.

Roof Truss Calculator

Compute rafter length, peak rise, and chord length from span and pitch.

Roof Shingle Calculator

Bundles and squares of asphalt shingles for any roof.