Drip Edge, Ridge Cap and Starter Calculator
Edge materials are bought by the linear foot. Enter your eaves, rakes, hips and ridges, and the coverage from the product wrapper.
Edge materials
Formulas
Eave and rake pieces are counted separately because they are cut and lapped separately at the corners, and many crews use a different profile on each.
Typical coverage (check your product)
| Product | Typical coverage | Notes |
|---|---|---|
| Drip edge | 10 ft pieces | Lap joints at least 2 in; type D (T-style) and type C (L-style) profiles |
| Hip & ridge cap shingles | ≈20–35 LF per bundle | Varies with exposure and piece size |
| Starter strip shingles | ≈100–120 LF per bundle | Some systems call for starter on rakes too |
| Ridge vent | 4 ft sections, or 20 ft and longer rolls | Stop short of hip and ridge ends per the vent instructions |
Worked example
Install notes
- The IRC requires drip edge at the eaves and rakes of shingle roofs, lapped at least 2 inches at joints.
- At eaves, drip edge goes under the underlayment; at rakes, it goes over it.
- Hip lines are longer than they look from the ground. On a regular hip roof, each hip is half the building width times the hip/valley factor (1.5 at 6/12).
Frequently asked questions
How many pieces of drip edge do I need?
Divide the eave length and the rake length by 9.83 ft (a 10 ft piece with a 2 inch overlap) and round each up. 100 ft of eaves takes 11 pieces.
How many linear feet does a bundle of ridge cap cover?
It depends on the product: roughly 20 to 35 linear feet per bundle. The wrapper lists the exact coverage.
Is drip edge required?
Under the International Residential Code, yes: shingle roofs need drip edge at eaves and rake edges. Check whether your jurisdiction adopted that section.
Last reviewed 2026-10-10. Results are estimates for planning; confirm quantities with your supplier and requirements with your local building code and the manufacturer's instructions.