What size downspout do I need?

Most homes use 2x3 or 3x4 inch rectangular downspouts. Choose 3x4 for 6-inch gutters, large roofs, steep pitches or heavy tree cover.

Are round or square downspouts better?

Neither is better overall. Rectangular downspouts suit K-style gutters and carry slightly more; round downspouts suit half-round gutters and traditional homes.

How far apart should downspouts be?

A common guide is one downspout for every 30 to 40 feet of gutter, but large or steep roofs and heavy rainfall need more.

Should downspouts match the gutters?

They usually match in material, but color can match either the gutters or the wall. Matching the wall makes downspouts less noticeable.

Materials

Downspout Types, Sizes, Materials and Colors

A gutter is only as good as the pipe that empties it. Downspouts that are too small, too few or badly placed are behind a large share of overflowing gutters, even when the gutter itself is the right size.

Updated 2026-10-26 · Gutter Fixing Editorial Team

Downspouts, also called leaders or conductor pipes, carry water from the gutter outlet to the ground or into a drain. They come in rectangular and round shapes, several sizes, and the same range of metals and colors as the gutters above them. Choosing them well is mostly about capacity and placement, with color and style as the finishing touch.

Downspout sizes: 2x3 and 3x4 gutter downspouts

Most American homes use rectangular, corrugated downspouts that pair with K-style gutters. The two common sizes are 2x3 inch and 3x4 inch. The larger size has about twice the cross-section of the smaller one, so it moves far more water and is much harder to clog with leaves, seeds and shingle grit. Installers often pair 2x3 downspouts with 5-inch gutters and 3x4 with 6-inch gutters, but upsizing to 3x4 on a 5-inch system is a cheap improvement wherever the roof is large or trees are close.

Downspout	Usual partner gutter	Notes
2x3 inch rectangular	5-inch K-style	Standard on many homes; clogs more easily
3x4 inch rectangular	6-inch K-style or busy 5-inch runs	Much higher capacity; good under trees
3-inch round	5-inch half-round	Traditional look; smooth inside
4-inch round	6-inch half-round	Higher capacity for large roofs
4x5 inch and larger	Commercial and oversized gutters	Used on large roof areas

Round downspouts

Round downspouts suit half-round gutters and traditional architecture. They may be plain or corrugated and are common in copper, galvanized steel and zinc. Round pipes connect to the gutter through a drop outlet and use round elbows and straps. Because the inside is smooth, debris passes through readily, though a round pipe of the same nominal size carries a little less than a rectangular one.

Aluminum, copper and other downspout materials

Aluminum downspouts: the standard choice with aluminum gutters, light, rust-free and available in every common color.
Copper downspouts: used with copper gutters; they age with the gutter and are often finished with decorative leader heads.
Galvanized and Galvalume steel: tougher against knocks at ground level and common on farm and commercial buildings.
Vinyl downspouts: cheap and easy to cut; best kept to vinyl systems on single-story buildings.
Zinc and stainless: used with matching gutters on architectural and coastal projects.

Downspouts should match the gutter metal. Mixing copper with aluminum, or steel straps on copper pipe, leads to corrosion and staining.

How many downspouts do you need?

A common rule of thumb is one downspout for every 30 to 40 feet of gutter, with runs longer than that sloped to a downspout at each end. The real number depends on how much roof drains to each gutter, how steep it is, and how hard it rains in your area. Steep roofs and heavy downpours call for more outlets. Adding a downspout is often the cheapest fix for a gutter that overflows in storms, cheaper than moving to a larger gutter.

Placement

Put downspouts at the corners where they can run down the house unobtrusively.
Avoid draining onto walkways, driveways and steps, where water freezes and stains.
Keep them away from doors and windows where splashing is a nuisance.
Do not drain an upper roof straight onto shingles below without a diverter or extension downspout.
Discharge at least several feet from the foundation, using an extension or an underground drain.

Elbows, offsets and straps

Downspouts rarely run in one straight drop. Elbows, labeled A or B depending on the direction of the bend, turn the pipe around overhangs and toward the ground. An offset pair of elbows with a short pipe between them steps the downspout from the gutter outlet back to the wall. Each elbow slows water and is a likely clog point, so the fewer the better. Straps should hold the pipe to the wall at the top, the bottom and every few feet between, with screws into solid material.

Downspout colors: black, white, brown and more

Downspouts usually match the gutters, but they do not have to. A popular look is gutters matched to the trim and downspouts matched to the wall color, so the pipes fade into the siding. On a white house with black gutters, white downspouts can soften the effect; black gutters and downspouts together make a bolder outline. Common stock colors include white, almond, brown, bronze, black and grey. The gutter colors guide covers pairing colors with siding and roofing.

Downspout accessories

At the bottom, a splash block or extension carries water clear of the house. Some homes add a diverter to fill a rain barrel, a flip-up extension that lifts out of the way for mowing, or a connection to a buried pipe. At the top, an outlet strainer or leaf catcher can stop debris from entering the pipe, though it needs regular emptying. The downspout extensions guide covers the options at ground level.

Signs a downspout needs attention

Water spilling over the gutter near an outlet, gurgling or pinging noises, wet ground at the bottom of the wall, and pipes that have come loose from their straps all point to a blocked, damaged or undersized downspout. Contractors in our network can clear, repair, upsize or add downspouts, and the downspout repair page explains what that work involves.

Downspouts for 4, 5 and 6 inch gutters

Small 4-inch gutters on porches and sheds normally take a 2x3 rectangular or 2-inch round pipe. Five-inch systems use 2x3 by default, though 3x4 fits the same outlet hole if it is cut larger and is worth it on busy runs. Six-inch gutters almost always take 3x4 or 4-inch round. The outlet, sometimes called a drop or a nozzle, must match the pipe size; a large downspout fed through a small outlet gains nothing.

Downspouts on two and three story homes

Tall drops carry water fast and put more weight on the straps. Fix them with straps at closer spacing, and where an upper downspout empties onto a lower roof, add a short gutter or diverter to spread the flow. A long run of exposed pipe on a tall facade is also a good place for a color that matches the wall.

Plastic, vinyl and PVC downspouts

Plastic and vinyl down spouts are sold with vinyl gutter systems in white, brown, grey and black. They are cheap and easy to cut, and PVC gutter downspouts will not corrode. They are less rigid than metal, so straps should be closer together, and in cold climates they can crack if struck. Many homeowners connect a downspout to PVC pipe underground; a gutter-to-PVC adapter joins the rectangular outlet to round 3-inch or 4-inch PVC downspout drain pipe.

Retractable, folding and hidden downspouts

A retractable or folding downspout bottom section flips up on a hinge so it is out of the way when mowing or walking past, then lowers again to carry water away. Hidden gutter downspouts run inside a wall, a column or a corner trim board on some modern homes; they look clean but must be large and accessible, because a clog inside a wall is hard to reach. Hidden gutters and downspouts are usually specified by the architect at design stage.

Decorative and square downspouts

Decorative down spouts include copper gutter spouts with leader heads at the top, lambs tongue downspout ends that curl outward at the bottom, and cast metal shoes. Square downspouts are plain, smooth-sided pipes used on modern and commercial buildings. Colored gutters and downspouts, from gray and bronze to black, can be matched or contrasted as the gutter colors guide explains. On metal buildings, gutters and downspouts usually come from the same panel maker in matching color.