Enter the length and width of the roof into the calculator to determine the total length of drip edge needed. This calculator can also evaluate any of the variables given the others are known.

## Drip Edge Formula

The following formula is used to calculate the length of drip edge needed for a roof.

DE = (2 * L) + (2 * W)

Variables:

- DE is the total length of drip edge needed (feet) L is the length of the roof (feet) W is the width of the roof (feet)

To calculate the total length of drip edge needed, multiply the length of the roof by 2, then multiply the width of the roof by 2. Add these two results together to get the total length of drip edge needed.

## What is a Drip Edge?

A drip edge is a metal flashing or strip installed at the edges of a roof to direct water away from the fascia and into the gutters. It is designed to prevent water damage to the roof deck, fascia, soffit, and the home’s foundation. It also helps to protect shingles from water damage and prevents wind-driven rain from getting underneath the roof covering.

## How to Calculate Drip Edge?

The following steps outline how to calculate the Drip Edge.

- First, determine the length of the roof (L) in feet.
- Next, determine the width of the roof (W) in feet.
- Next, use the formula DE = (2 * L) + (2 * W) to calculate the total length of drip edge needed (DE) in feet.
- Finally, calculate the Drip Edge.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

length of the roof (L) = 20 feet

width of the roof (W) = 15 feet