Gutter Sizes Explained: 5", 6" or 7" — Which One Do You Need?
Gutter size is measured across the top opening. Most houses in the GTA have 5" K-style aluminum gutters, but larger and steeper roofs often need 6" or even 7" gutters to handle a heavy summer storm.
Quick guide
- 5" K-style with 2"×3" downspouts — standard for most bungalows and two-storey homes with a moderate roof pitch.
- 6" K-style with 3"×4" downspouts — large roof areas, steep roofs, long runs, or homes under trees. Holds about 40% more water than 5".
- 7" commercial — very large roofs, flat or low-slope commercial buildings, and places where overflow keeps happening.
Other things we check
- Where the downspouts go and how many there are — an extra downspout often solves overflow without bigger gutters.
- The slope of the gutter toward each outlet.
- Fascia condition — rotten wood must be fixed before new gutters are hung.
- Colour matching your trim, soffit and roof.
We install seamless gutters in any size, formed on site to the exact length of your roof, plus downspouts, leaf guards and extensions. Ask for a free quote and we will measure and recommend the right size.
More guides: How often to clean gutters · Signs of a clogged downspout · Ice dams & winter gutters · Fixing leaking gutter seams