Ridge · Hips · Valleys · Cut-Ups

Hip & Ridge Cap Shingle Calculator

A ridge cap shingle calculator that works the way caps actually get ordered — in linear feet, not squares. Enter the ridge and each hip line, pick a cap product from 20 to 33 lf per bundle (or the 3-tab cut-up route), and get the bundle count with waste already applied.

Presets:

Cap Line Inputs

Ridge length (lf)

Valley length (lf)

Measure up the slope, not on the plan — a 6/12 stretch adds 11.8%. Valleys are tracked for the field note below, never for caps.

Hip count

Hip length each (lf)

Cap product

Cap waste factor

10%

Always confirm the wrapper: lf-per-bundle varies by product line even within one brand. The options here are the site’s standard planning values.

Your Cap Order

96 lf

Cap line — 40 lf ridge + 56 lf hips

Bundles @ 25 lf each (+10% waste)

3-tab bundles if cut into caps

≈ 120

Cap pieces → nails (1 each)

106 lf

Ordered length incl. waste

16 ft²

Valley load on FIELD shingles

Your 16 lf of valley consumes about 16 ft² of field shingles (≈ 0.5 bundle) — that belongs in the field count from the roof shingle calculator, never in the cap order.

Planning a full roof too? The homepage roof shingle calculator produces the field bundle count, and the roofing calculators hub covers every special case on the site.

Product Lines

Ridge Cap Coverage by Product Line

The same 40 lf ridge orders two bundles or three depending entirely on which wrapper you grab. This table pre-computes the answer for the site’s five planning coverages at 10% waste — read the wrapper, find the row, and the bundle count is settled.

Cap product	lf per bundle	Bundles for 40 lf ridge	Nails per cap	Notes
Manufactured cappre-bent, factory-sealed	20 lf	3 bundles	1 per cap piece	Economy profile — check wind rating
Manufactured cappre-bent, factory-sealed	25 lf	2 bundles	1 per cap piece	Standard profile, most common wrapper
Manufactured cappre-bent, factory-sealed	30 lf	2 bundles	1 per cap piece	Standard profile, most common wrapper
Manufactured cappre-bent, factory-sealed	33 lf	2 bundles	1 per cap piece	Premium profile — often the same shingle line as the field
3-tab cut-up capssite-made from 12×36 strips	35 lf	2 bundles	1 per 12 in piece	Site-made from 3-tab strips — add sealant beads

Bundle counts include 10% cutting waste (40 lf → 44 lf ordered). Nailing shown is the standard pattern; high-wind specifications double it to 2 per piece and 130 mph ratings call for 4 — check the product’s installation sheet.

💡 Tip: match the cap line to the field line when the manufacturer offers it — a color-matched cap from the same product family blends better than a generic cap and keeps the enhanced warranty intact.

⚠️ Warning: 3-tab cut-up caps carry no factory sealant. On exposed ridges they need a sealant bead under every lap — skip it and the first gust-driven rain finds the ridge line from inside the attic.

❌ Don’t: buy caps “per square of roof.” Two 28-square houses can differ by 60 lf of ridge and zero difference in squares. Caps order by measured lf — always have, always will.

Cut-Up Roof Accessory Takeoff (40 × 30 Hip @ 6/12)

A worked example of the whole method on one roof: the ridge, four hips, and two woven valleys of a 40 × 30 hip roof, with every line converted to bundles at a 20 lf economy cap. Note where the valleys land — in the field column, not the cap column.

Line item	Length (lf)	Bundle conversion	Waste %	Order qty
Ridge cap	40 lf	40 ÷ 20 lf = 2.0 bdl	+10%	3 bundles (44 lf)
Hip caps (4 hips)	4 × 14 = 56 lf	56 ÷ 20 lf = 2.8 bdl	+10%	4 bundles (62 lf)
Valleys (2, woven)	2 × 8 = 16 lf	≈ 1 ft² field shingle per lf → 16 ft²	in field count	0 cap bundles
Cap total	96 lf	96 ÷ 20 lf = 4.8 bdl	+10% → 106 lf	7 bundles

The 7-bundle cap total at 20 lf economy coverage drops to 5 bundles at 33 lf premium cap — rerun the calculator above with a different product to see the same roof repriced in one click. Hip lengths here are slope measurements; the 6/12 multiplier is already inside them.

Measuring the Cap Lines Without Guessing

How to calculate hip and ridge shingles when the roof is still a plan drawing: take every cap-carrying line from the plan view, then stretch each one by the pitch multiplier. Ridges stretch by exactly the same multiplier as the field — √(1 + (rise/12)²), which is 1.118 at 6/12 and 1.202 at 8/12. Hips stretch slightly more than ridges at the same pitch, because the hip’s horizontal run is the diagonal of the two plane slopes; for equal-pitch roofs the hip multiplier is √(2 + (rise/12)²) over the plan’s half-diagonal — 1.172 at 6/12. The worked 40 × 30 example above already carries those stretches inside its lf column, which is why its hips read 14 lf where the plan suggests 12.6.

On the roof: hook a tape at the ridge start and walk the line — fastest and exact, and it catches dog-leg ridges a plan hides.
From the ground: a simple gable's ridge can be paced from the street against a known siding course; complex hip layouts deserve the ladder or the plan math — a missed 12 lf hip is a full missing bundle.
From the plan: ridge lf × pitch multiplier, plus hip count × (half-diagonal × hip multiplier). Round every line up to the nearest foot before summing.
Then add the waste: 10% for manufactured caps on straightforward runs, 15% when hips bend over mixed pitches or the gazebo-grade geometry of the octagon calculator.

Myth vs Fact

Four Cap Estimating Myths That Cost Real Money

Cap errors are small-ticket per bundle and reputation-expensive per job: a two-bundle shortage stops the crew at the last ridge, and the second trip usually costs more than the caps. These are the four mistakes this calculator is engineered to make impossible.

Myth: Valleys need cap shingles too.

Fact: Valleys are the one roof line that never takes caps. A woven or closed-cut valley consumes roughly 1 ft² of field shingle per linear foot — 16 lf of valley is 16 ft² of field, about half a bundle that should already be in your field count. The valley accessory list is metal or self-adhering underlayment, not caps.

Myth: One cap bundle covers one bundle-worth of ridge.

Fact: Field bundles cover 33.3 ft² of area; cap bundles cover 20 to 35 LINEAR feet depending on the product. At 33 lf per bundle a 40 lf ridge is 2 bundles; at 20 lf it is 3. Quoting caps from an area habit is the most common cap shortage on job sites.

Myth: Cutting up 3-tab gives you the same cap as manufactured.

Fact: A 12 × 36 3-tab strip cuts into three 12 × 12 cap pieces — about 35 lf per bundle — but each piece is a right angle with no factory sealant. On a 90° ridge it works with added sealant beads and careful nailing; on the shallower bends of hips it gaps. Manufactured caps are pre-bent and pre-sealed for a reason.

Myth: You measure the ridge on the floor plan.

Fact: Caps are measured UP the slope. A ridge that reads 24 ft on the plan runs 24 × 1.118 = 27 lf at 6/12 — a 12% stretch that consumes an extra bundle on longer roofs. Every lf in this calculator is a slope measurement; measure on the roof or compute from pitch, never from the plan view.

Roofer installing manufactured ridge cap shingles along the hip line of an asphalt roof

Caps are measured in lf, not squaresPhoto: Unsplash

The 3-Tab Cut-Up Method, Done Right

Every 12 × 36 strip of 3-tab cuts into three 12 × 12 cap pieces — roughly 35 lf of finished cap per bundle — which makes cut-ups the cheapest cap in roofing and, on mixed-pitch hips, sometimes the best-fitting one. The discipline is in the details: snap the tabs cleanly, taper the hidden corners so pieces nest over the ridge bend, nail once per piece where the next piece will cover, and run a sealant bead under the exposed laps. The calculator’s 35 lf option converts your measured lf into exactly how many 3-tab bundles the bucket needs.

Manufactured caps flip those economics on long straight ridges: pre-bent, pre-sealed, faster to lay, and color-matched — at two to four times the material cost per lf. On a 40 lf gable the labor saved is real; on a gazebo’s eight hand-cut hips (see the gazebo shingle calculator), site-cut pieces often win on fit regardless of price.

Hip & Ridge Cap Questions

How do you calculate ridge cap shingles?

Ridge cap is a linear calculation with three steps: measure the ridge length in feet up the slope, add every hip line measured the same way, then divide the total by the lf-per-bundle printed on the cap wrapper and round up. A 40 lf ridge plus four 14 lf hips is 96 lf of cap line; at a 25 lf standard cap that is 3.84, which orders 4 bundles. Add 10% for cutting waste on manufactured caps — more if the roof has many short hip segments, because each segment end eats a partial piece. Valleys are excluded: they consume field shingles at roughly 1 ft² per lf, not caps.

How many bundles of ridge cap do I need for a 40-foot ridge?

Two to three bundles depending on the product: at 33 lf per bundle, 40 × 1.1 waste = 44 lf orders 2 bundles; at 25 lf it orders 2 bundles (50 lf); at 20 lf economy cap it orders 3 bundles (60 lf). The quick check is wrapper lf × bundles ≥ measured lf + 10%. If the ridge is a true 40 ft of slope length — which a 40 ft plan ridge at 6/12 is not, being 44.7 ft — the numbers shift up one bundle at every product, which is why the calculator measures up the slope.

How do you make ridge cap shingles from 3-tab?

The cut-up method: take a standard 12 × 36 3-tab strip, snap it on the tab lines into three 12 × 12 pieces, then cut a slight taper off the back corners of each so the pieces nest around the ridge bend. One bundle of 3-tab yields about 35 lf of cap this way — 26 strips, 78 pieces at 12 in of coverage each. Install them with the reveal facing the prevailing weather, one nail per piece placed so the next piece covers the nail head, and a bead of roofing sealant under the leading edge; without the sealant, wind-driven rain walks straight up the unsealed laps.

Do valleys count in the ridge cap calculation?

No — and this is the most repeated cap estimating error. Open valleys need metal or membrane plus woven or closed-cut shingles from the field supply: a woven valley consumes about 1 ft² of field shingle per linear foot (16 lf of valley ≈ 16 ft², half a bundle). Closed-cut valleys consume slightly less, open-with-metal slightly more because each side terminates against the metal. None of it comes out of cap bundles. Count valleys separately, keep them in the field order, and keep the cap count to ridge plus hips.

How many nails does a ridge cap line take?

One nail per cap piece on standard installs — a manufactured 25 lf bundle holds about 24 pieces, so a 96 lf job with waste is roughly 106 nails plus spares; buy a full box of 1¾ in ridge nails. In high-wind installations the pattern doubles to a minimum of two nails per piece, and manufacturer specs for the 130 mph ratings call for four — the cap is the first line to peel in uplift, so the fastener count is not optional fine print. Ring-shank nails buy meaningful holding power on caps for pennies per bundle.

What is the difference between a hip cap and a ridge cap?

The product is usually the same — manufactured hip/ridge cap serves both — but the geometry differs. Ridges are near-90° bends between two equal slopes; hips are shallower bends between planes of different pitch, so cap pieces have to splay wider and cut waste runs higher on hip-heavy roofs. Steep-slope hips at mixed pitches are where site-cut 3-tab pieces actually fit better than rigid manufactured caps. Measure hips up the slope exactly like ridges, budget a little more waste, and use the same lf-per-bundle division.