Gutters come in many sizes.
How many downspouts on long gutter run.
Particularly wet climates could require better drainage systems than relatively dry climates rainy.
Most gutter installers add a downspout about every 20 or 30 feet of gutter although depending on the slope of your roof and the rooflines you may need more.
Write out all of your measurements.
Or 3200 square feet of roof is calculated as 3200 1200 2 67 rounding up you would need 3 3x4 downspouts one 2x3 downspout will drain 600 sq.
Large gutters can hold more water and may not need as many spouts.
If i could do it all over again i would have used 3x4 size downspouts the 2x3 size just can t handle these 100 year storms.
One 3x4 downspout will drain 1200 sq.
How many downspouts do i really need.
If your old gutter system worked well you may find it easiest to simply copy that exact system and replace it with a new one keeping the old downspouts in the same area etc.
Smaller gutters may need extra downspouts to make up for their low volume.
In areas with heavy rainfall your installer may also determine that for optimal flow you want downspouts on each end of a gutter run even if it.
Heavy rainstorms put a lot more pressure on gutters.
The above recommendations assume that you have properly sized downspouts every 40 feet.
If the run is more than 35 feet long some specialists recommend installing the high point of the system in the middle and sloping the gutter downward in both directions to downspouts on both ends.
Increase the pitch of the gutter.