It is easy to see that you can vary gutter size downspout size and downspout spacing to properly size a gutter downspout system.
Downspout gutter sizes.
Most downspouts are rectangular but they can also be round or square.
Five inch k style gutters or 6 inch half rounds the most common residential sizes are able to handle the rainfall on most houses in most parts of the country.
The larger a gutter downspout the more water it can drain quickly.
However too large a gutter downspout can look unattractive.
Gutter downspout sizes are 3 to 6 inches.
It also comes in sizes 2 3 and 3 4.
This is the standard downspout style used on homes with the 5 k style gutter system.
The second most common style of downspouts in urban homes is the rectangular downspout coming under a range of sizes such as 2 3 3 4 and 4 5.
Available sizes are 2 3 and 3 4.
But houses with big steep roofs or those located in climates prone to heavy downpours may need wider gutters and extra downspouts to keep rainwater from overflowing.
You should have enough gutter downspouts to effectively handle the size of your entire gutter system.
By reducing the downspout spacing to perhaps 35lf you could use a 6 gutter with 9 4 x6 downspouts in lieu of an 8 system.
They come in various colors and sizes of 3 4 5 and 6.
Round 3 inches 706 square feet 4 inches 1 255 square feet.