Half round gutters
By Gutter Report Editorial. Last reviewed August 2026. How we research this.
In brief
A half round gutter is a semicircle, and it is the older of the two common profiles. It costs about $1 to $2 a foot more than K-style in the same material, per HomeGuide, and Angi and Fixr both show a gap that size. Only Modernize puts it higher, at $4 to $5. In aluminum the metal itself runs $3.58 a foot for 5 inch and $4.73 for 6 inch at a specialist supplier, against roughly $6.00 and $8.90 for the same sizes at a big box store. Sizes run 4 to 8 inches, with 5 and 6 covering most houses. The rounded bottom sheds debris better than a flat one. The real trade-off is capacity: at the same nominal width, published figures give half round less drainable roof area than K-style, though the published numbers do not agree with each other.
1.0What half round costs
Nobody prices half round as its own product. Every publisher prices it as a premium over K-style in the same metal.
| Source | K-style | Half round | Premium |
|---|---|---|---|
| USD / FT | USD / FT | USD / FT | |
| HomeGuide, all materials, stated outright | n/a | n/a | +$1 to $2 |
| Angi, seamless, installed (2026) | $8 to $15 | $9 to $17 | +$1 to $2 |
| Fixr, copper, installed (Jan 2025) | $26 to $37 | $27 to $40 | +$1 to $3 |
| Modernize calculator (Aug 2026) | $9 to $30 | $13 to $35 | +$4 to $5 |
Three of four agree on a $1 to $2 premium. That is small next to the material decision: moving from aluminum to copper costs $15 to $30 a foot more, ten times the profile premium.
HomeGuide also splits aluminum material cost by profile and width, on a page that carries 2026 in the title and a 2022 publication date. It gives 5 inch K-style at $1 to $4 a foot and 5 inch half round at $3 to $5, then 6 inch K-style at $2 to $5 and 6 inch half round at $5 to $6. European style half round is higher again at $5 to $7 and $7 to $9. Price your own run with the cost calculator.
2.0What the metal costs, by seller
Half round is where the gap between a specialist supplier and a big box store gets wide, and it is worth seeing before you read a quote. All read 2026-08-21.
| Item | Classic Gutter Systems | The Home Depot |
|---|---|---|
| USD / FT | USD / FT | |
| 5 in. aluminum, .027 | $3.58 | $6.00 |
| 6 in. aluminum, .032 | $4.73 | $8.90 |
| 8 in. aluminum, .032 | $7.15 | not stocked |
| 5 in. Galvalume, 26 ga. | $3.58 | not stocked |
| 6 in. Galvalume, 26 ga. | $4.73 | not stocked |
| 5 in. copper, 16 oz | $10.94 | $15.03 |
| 6 in. copper, 16 oz | $13.03 | $16.98 |
| 5 in. copper, 20 oz | $12.04 | not sold in 20 oz |
| 8 in. copper, 20 oz | $19.25 | not stocked |
Home Depot figures are our arithmetic, dividing its 10 foot Amerimax sections by 10. On the 5 inch aluminum row that is a 68 percent premium for the same .027 spec. Half round is a specialty item at a big box store and a stock item at a gutter supplier, and the pricing shows it.
Two more notes from those listings. Color costs money: Classic charges $4.51 a foot for its coppertone finish against $3.58 for standard colors, and at Home Depot the brown 6 inch aluminum is $99.98 per 10 feet against $88.98 for white. And a seamless half round exists in aluminum: Seamless Gutter Supply sells 6 inch reverse bead by the foot at $5.44.
3.0Sizes, beads and backs
Half round is ordered by diameter and by bead style, and the bead is the part people forget.
| Spec | What is offered |
|---|---|
| Diameters | 4 to 8 in. Most houses use 5 or 6 |
| Berger stock | 5 and 6 in. in aluminum, copper and galvanized. 7 and 8 in. in limited metals on request |
| Bead styles | Single bead, single bead with 1 in. flange, double bead, reverse bead |
| Aluminum thickness | 5 in. at .024 and .027, 6 in. at .032. Reverse bead 6 in. at .027 |
| Copper weights | 5 and 6 in. single bead in 16 oz and 20 oz. Double bead in 16 oz. Reverse bead 6 in. in 16 oz |
| Galvanized steel | 5 and 6 in. in 24 and 26 gauge |
Match the bead if you are extending or repairing an existing run. Seamless Gutter Supply's 6 inch copper reverse bead runs $20.42 a foot while Classic's 6 inch classic bead runs $13.03, and part of that 36 percent gap is the different bead profile rather than pure seller markup.
4.0The capacity question, and why the numbers fight
This Old House states that half round lets water flow more smoothly than K-style but generally carries less volume at the same width. Its own published roof area figures are where it gets strange.
| Gutter | Maximum drainage area |
|---|---|
| SQ FT of roof | |
| 5 in. K-style | 5,520 |
| 6 in. K-style | 7,960 |
| 5 in. half round | 2,500 |
| 6 in. half round | 3,840 |
A 5 inch half round is a 5 inch wide semicircle, which works out to about 9.8 square inches of cross section. That arithmetic is ours. The 2.2 times gap in the table above is not a measured difference between two gutters: the 2,500 figure matches a legacy semicircular plumbing code value for a 5 inch gutter at 1/4 inch per foot slope, while 5,520 traces to a Fine Homebuilding article about K-style at a different basis. Two tables, never meant to be read as one.
One more thing that page leaves out. Fine Homebuilding, the original source for 5,520, states the basis: 1 inch of rain per hour. Its own worked example divides that by Washington DC's 6.6 inch per hour five minute intensity and lands on 836 square feet of real maximum roof area. Any page reprinting 5,520 as a usable roof area, without that division, is off by roughly seven times.
The practical takeaway is unchanged: at the same nominal size, treat half round as the smaller gutter and size up or add a downspout if the roof is large. What you should not do is pick a profile off a roof area table that no publisher can reconcile.
Hanging half round is different work
A K-style gutter has a flat back that screws to the fascia. A semicircle has no flat back, so it hangs in brackets or straps instead, and those are priced per piece.
| Stamped half round fascia bracket | Price each |
|---|---|
| USD | |
| 5 in., Galvalume | $3.85 |
| 5 in., chromated aluminum | $4.18 |
| 6 in., Galvalume | $6.80 |
| 8 in., Galvalume | $8.75 |
| 5 in., copper | $10.45 |
| 6 in., copper | $13.64 |
| 8 in., copper | $16.50 |
Classic Gutter Systems sells these and recommends 32 inches on center. On 150 feet of gutter that is about 57 brackets. At $3.85 each the hardware runs roughly $220 in Galvalume and about $600 in copper. A copper bracket costs 2.7 times the Galvalume one of the same size. On copper you have to use copper or brass anyway. The Copper Development Association specifies brass or copper brackets, and mixing metals in a wet assembly invites corrosion.
End caps are priced per piece too, and they are cheap: 5 inch aluminum at $4.40, 5 inch galvanized at $4.44, 5 inch copper at $7.90 and 6 inch copper at $8.77. Copper end caps get soldered rather than sealed, which is a different skill.
5.0How long it lasts, by material
The profile does not set the service life. The metal does. This Old House publishes this set on its own half round page.
| Material | Service life |
|---|---|
| YEARS | |
| Vinyl | 10 to 15 |
| Galvanized steel | 15 to 20 |
| Aluminum | 20 to 30 |
| Zinc | 50 |
| Copper | 100 |
Note this is the same publisher giving galvanized steel 15 to 20 here while its main cost page says 20 or longer. Those disagreements are covered on each material page.
6.0You may not need half round
Half round is chosen for two honest reasons: the house is a period style where the ogee face of K-style looks wrong, or you want the rounded bottom that sheds debris better. Both are real. Neither is a performance upgrade.
If you are switching profiles to fix overflow, stop. Overflow is slope, a clog, or too few downspouts, and half round is the profile with less capacity at the same width, so switching can make it worse. Size up or add an outlet instead. See 5 inch against 6 inch for that decision.
And if the run you have is basically sound, price a repair at a national average of $275 first. A profile change means new hangers, new brackets and new downspout outlets along the whole house. We can say that plainly because we do not sell gutters and we do not install them.
Get a half round gutter quote from a licensed contractor
Half round hangs in brackets rather than on the fascia, so ask how many and at what spacing. Tell us your ZIP code and we will pass your details to one licensed contractor who works there.
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Common questions
How much do half round gutters cost?
HomeGuide says half round adds $1 to $2 a foot over K-style in the same material. Angi agrees, pricing seamless K-style at $8 to $15 a foot installed against half round at $9 to $17. Fixr shows the same $1 to $3 gap on copper. Modernize is the outlier at $13 to $35 for half round against $9 to $30 for K-style, a $4 to $5 premium. So expect a small premium in most quotes, not a different price class.
Do half round gutters hold less water than K-style?
This Old House says yes. It writes that half round lets water flow more smoothly but carries less volume at the same width. Its own roof area figures are harder to square with that. It gives a 5 inch K-style 5,520 square feet and a 5 inch half round 2,500. That is a 2.2 times gap at the same width. The two numbers trace to different tables that were never meant to sit together. Read the gap as a publishing artifact, not a measured difference.
What sizes do half round gutters come in?
Common diameters run 4 to 8 inches, and most houses use 5 or 6, per This Old House. Berger Building Products stocks 5 and 6 inch half round in aluminum, copper and galvanized steel, and offers 7 and 8 inch in limited metals on request. Classic Gutter Systems lists 8 inch in aluminum and in 20 oz copper.
What is a bead on a half round gutter?
The rolled edge at the top of the semicircle, and the style of it is a real ordering choice. Berger and Amerimax both list single bead, single bead with a 1 inch flange, double bead and reverse bead. Reverse bead turns the lip outward and is the one usually seen on newer installs. Match the bead to any existing run before you order.
Are half round gutters easier to clean?
The rounded bottom helps. Texas A&M AgriLife Extension recommends rounded bottom gutters because they limit debris buildup, and This Old House agrees water moves more smoothly through them. There is no flat floor and no inside corner for grit to sit in. It does not make them self cleaning, and leaves still land in them.
Why are half round gutters on old houses?
Because they came first. The semicircle is the older profile, and it is what fits the trim on a Colonial, Victorian, Tudor or Craftsman without looking wrong. K-style, with its ogee face, is a twentieth century profile that reads as modern on a period house. On copper especially, half round is the shape most people picture.
- Rev
- RevAugust 2026
- Source
- SourceHomeGuide, Angi, Fixr, Modernize, Berger, Amerimax, Classic Gutter Systems, This Old House (read 2026-08-21)