Ridge Cap Calculator: Bundles for Ridges & Hips
Add up the linear feet of ridges and hips and enter the coverage per bundle to get the number of ridge-cap bundles to order. Cap is what finishes the peaks of the roof and it is bought and counted separately from your field shingles.
Calculator
60 LF of ridge and hips at 25 LF/bundle needs 3 cap bundles.
Ridge cap is the row of shingles that folds over the peaks of the roof — the horizontal ridges and the diagonal hips where two slopes meet. Because cap protects the most exposed lines on the roof and is bent over an edge, it is measured in linear feet, not in area, and it is bought separately from your field bundles.
Dedicated hip-and-ridge cap product typically covers about 25 to 33 linear feet per bundle depending on the brand and the exposure. Some roofers instead cut cap from standard three-tab field shingles, which changes the coverage — so this tool lets you enter whatever coverage your chosen product or method gives. To find the field shingles for the rest of the roof, use the bundle calculator.
Formula
Bundles are total cap length over the coverage per bundle, rounded up:
bundles = ⌈ (ridge_lf + hip_lf) ÷ coverage_per_bundle ⌉
- ridge_lf + hip_lf — every ridge and hip line added together, in linear feet.
- coverage_per_bundle — LF one bundle of cap covers (≈ 25–33 for dedicated cap).
- ⌈ ⌉ — round up to whole bundles.
Worked example
Cap a roof with 40 ft of ridge and 20 ft of hips, using cap that covers 25 LF per bundle:
- Total cap length: 40 + 20 = 60 LF.
- Bundles: 60 ÷ 25 = 2.4, rounded up to 3 bundles.
Three bundles finish all the peaks with a little to spare. If your cap product covers 33 LF per bundle instead, the same 60 LF only needs 2 bundles — which is why the coverage input matters.
Ridge & hip notes
Getting cap quantities right:
- Measure hips and ridges carefully. Walk the roof plan and total every peak line. Hips are longer than they look on a flat drawing because they run up the slope — use your rafter or slope length, not the flat plan length.
- Dedicated cap vs. cut three-tab. Purpose-made hip-and-ridge shingles are thicker and give a cleaner line; cutting cap from three-tab field shingles is cheaper but covers differently. Enter the matching coverage.
- Account for ridge vent. If a section of ridge gets a ridge vent, cap still goes over the vent, so keep it in your length — but the vent itself is a separate item.
- Longer nails on cap. Cap sits over built-up layers at the peak, so it usually needs longer nails than the field — see the nail calculator.
Reference table
Cap bundles by total ridge + hip length at 25 LF/bundle:
| Ridge + hip | Bundles |
|---|---|
| 30 LF | 2 |
| 45 LF | 2 |
| 60 LF | 3 |
| 75 LF | 3 |
| 90 LF | 4 |
| 120 LF | 5 |
Frequently asked questions
How many bundles of ridge cap do I need?
Divide the total linear feet of ridges and hips by the coverage per bundle, then round up. For 60 LF of peaks with cap that covers 25 LF per bundle, 60 ÷ 25 = 2.4, so you need 3 bundles.
How much does a bundle of ridge cap cover?
Dedicated hip-and-ridge cap typically covers 25 to 33 linear feet per bundle, depending on the brand and exposure. Cap cut from standard three-tab shingles covers a different amount, so always use the coverage stated for the product you are actually installing.
Can I use regular shingles for ridge cap?
You can cut cap from standard three-tab field shingles, and many roofers do to save money. Purpose-made hip-and-ridge cap is thicker, bends over the peak more cleanly and often looks better on architectural roofs. Either way, enter the coverage that matches your method.
Do I measure hips the same as ridges?
Add both into one total, but measure hips along the slope, not the flat plan. A hip runs up the roof, so its true length is longer than it appears on an overhead drawing — use the rafter or slope length for an accurate figure.
Is ridge cap counted in my field shingle order?
No. Ridge cap is bought and counted separately from the field shingles that cover the slopes. Size your field bundles with the bundle calculator and add cap on top.