Ridge Cap Calculator
Calculate how many bundles of ridge cap you need from your ridge and hip lengths. Works with specialty ridge cap shingles or three-tab shingles cut on site — both coverage figures stay adjustable.
Inputs
Enter at least one length. Hip roofs usually have no ridge cap on the eave side, but every hip needs capping.
Results
Ridge Cap Bundles Needed
- Total Ridge + Hip
- With Waste
- Coverage Used
What would you like to calculate next?
Enter your ridge and hip lengths, then press Calculate.
How to Calculate Ridge Cap
Ridge cap covers two things: the ridge at the top of the roof and every hip running down a corner. Measure each in linear feet and add them together. Ridge cap shingles are sold in bundles — a specialty ridge cap bundle typically covers about 33 linear feet.
Ridge Cap Formulas
Total length
40 ft ridge + 24 ft hip = 64 ft
Bundles
64 × 1.10 ÷ 33 = 2.13 → 3 bundles
Worked Example
A hip roof with a 40 ft ridge and 24 ft of total hip length needs 64 linear feet of ridge cap. With 10% waste that is 70.4 linear feet. At 33 linear feet per bundle you need 2.13 bundles, so order 3 bundles.
Measuring 3 Methods
Method 1 — From the ground
Pace off the ridge line and convert steps to feet (about 2.5 ft per step). Fast but rough.
Method 2 — From plans
Read the ridge dimension from the roof plan. The most reliable if plans match the building.
Method 3 — On the roof
Tape measure along the ridge and each hip. Most accurate, and required for complex roofs.
What You Need
Your ridge length and total hip length in feet (hip length can be left at 0 for a gable roof — gables have a ridge but no hips), plus the coverage figure from your ridge cap product or the three-tab bundles you plan to cut.
Assumptions & Limitations
Coverage per bundle varies by product; the default 33 linear feet is a typical specialty ridge cap figure. Three-tab shingles can be cut into ridge cap but may not match the field shingle profile exactly. This calculator does not include ridge vent material. Planning purposes only.
Frequently Asked Questions
How many linear feet does a bundle of ridge cap cover?
A typical specialty ridge cap bundle covers about 33 linear feet. Three-tab shingles cut on site yield roughly 35 linear feet per bundle.
Do I need ridge cap on a hip roof?
Yes — every ridge and every hip needs capping. Hip roofs often need more ridge cap than gable roofs because hips add length, even when the ridge itself is shorter.
Can I use cut three-tab shingles as ridge cap?
Yes, three-tab shingles are commonly cut into three pieces and used as ridge cap, especially on budget projects. Specialty ridge cap looks better and lasts longer because it is designed to bend.
Related Calculators
Drip Edge Calculator
Calculate how much drip edge you need: roof perimeter plus corner overlaps, in linear feet and 10-foot pieces, with waste factor.
Starter Strip Calculator
Calculate starter strip rolls from your eave length, using self-adhered starter rolls or three-tab shingles cut into starter pieces.
Roofing Nails Calculator
Calculate roofing nails from squares and ridge length. Choose 4-nail or 6-nail patterns and get coil boxes to order.
Sources & Methodology
- NRCA — National Roofing Contractors Association, Roofing Manual: Steep-slope Roof Systems — industry-standard roof geometry, roofing square and installation conventions
- Manufacturer installation instructions (asphalt shingle & metal roofing systems) — bundles per square, fastener schedules and accessory coverage vary by product — always confirm against the product data sheet
- ASTM D3462 — Standard Specification for Asphalt Shingles Made from Glass Felt — asphalt shingle product specification referenced by manufacturer installation instructions
Quantity dataset p2-data-1 (manufacturer packaging specifications, reviewed quarterly).
Formulas, assumptions and rounding rules: Methodology · Last updated: September 2026 · Calculation Engine: p1-v1 · Published by the RoofCalcWorks Editorial Team.