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Percent grade to degrees (and degrees to percent)

Slope is often written as percent grade (like 12%), while angle tools read degrees. This guide shows how to convert both ways, relate the result to pitch (x/12), and sanity-check on an image.

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Percent grade vs degrees (quick definitions)

Percent grade (%) describes rise divided by run, multiplied by 100. Example: 12% means 12 units of rise per 100 units of horizontal run.

Degrees describe the angle between the slope line and a true horizontal baseline.

Pitch (x/12) is another way to express rise/run. Once you can measure degrees, you can compare it to percent grade and pitch values used in plans or specs.

Step-by-step

  1. 1
    Pick the input format
    Decide whether you’re starting from percent grade (%), degrees, or pitch (x/12). Choose the conversion direction you need for your spec or check.
  2. 2
    Upload an image to verify (optional)
    If you have a ramp/roof/stairs photo or a plan, upload it so you can verify the slope angle visually before converting.
  3. 3
    Align a true horizontal baseline
    Rotate/flip and use the grid so a known horizontal edge is perfectly level. Degrees always reference true horizontal.
  4. 4
    Measure the slope in degrees
    Place the center at the slope start point. Keep one side aligned to horizontal, rotate the other side to match the slope edge, then read the angle.
  5. 5
    Convert, compare, and export
    Convert degrees ↔ percent grade (and compare to pitch x/12 if relevant). Export PNG/PDF once your image and numbers agree.

Tips

  • Plans and screenshots usually convert better than photos. Photos can bias slope if shot at an angle.
  • Baseline alignment matters more than snapping. Fix horizontal first, then measure and convert.
  • Use the same units for rise/run when you think in % or pitch (it’s a ratio, so units cancel out).
Alignment checklistRoof pitch to degrees (and degrees to pitch)Degrees vs radians (basics)

Related

Measure ramp slope angle
Measure ramp slope degrees from a photo or plan, then compare to percent grade requirements.
Measure stair stringer angle
Measure a stair slope angle and sanity-check it against drawings and specs.
Measure roof pitch (slope) angle
Measure roof slope in degrees from a photo or plan, then convert to other formats.
PNG and PDF exports
Save a shareable image or a report once your slope conversion is verified.
Percent Grade to Degrees (and Degrees to Percent) | Smart Protractor