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Soffit Drop Calculator   Calculate distance from top of wall to under soffit (Soffit Drop) and Floor Level to Soffit.

Roof Angle °
Soffit Width
Top Fascia to Under Soffit
Fascia Thick
Rafter Depth
Batten Thick
Birds-mouth Plumbcut
Floor to Wall Top

Angle Soffit Wall Birds-mouth
Roof soffit drop calculator diagram

The Top Fascia to Under Soffit measurement is from top of fascia (under roof sheeting) to the bottom side of the soffit sheeting. The calculated Soffit Drop is the measurement from top of wall vertically down to the underside of soffit sheeting.

The Wall Top to Rafter Bottom measurement is from top of wall vertically down to a point level with the bottom outside edge of the rafter (not including Fascia).

Need these calculations on-site? Try the site with a Smart Phone or Tablet. With a phone or tablet, you can directly measure angles for input to the Roofing and Pitch Angle calculator apps.

Lay the device on an incline and tap to measure angle. Tap again to capture angle and auto calculate roof, pitch, angles etc.

Hit the Speech button and your device will repeatedly speak the current measured angle, so you don't need to see the screen to find the angle.
The buttons appear automatically when you visit with a device capable of pitch measurement.

DON'T BREATH THE DUST If you're cutting blocks, concrete, stone or ANYTHING and there's DUST - DON'T TAKE THE RISK
Don't cut it, or cut it wet so there's NO DUST - Silicosis Sucks

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All calculators on this site are geometric only.
Check relevant local regulations for appropriate sizes, spacings and all engineering requirements.

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