What size gutters do I need for my house?

Gutter size depends on roof area, pitch, and local rainfall intensity. For most homes, 5-inch K-style gutters handle up to 2,200 sq ft of roof area in moderate rainfall. Homes in heavy rain zones like Myrtle Beach or with larger roofs need 6-inch gutters. The formula is: (Roof Area × Pitch Factor × Rainfall Intensity) ÷ 96.23 = GPM drainage needed.

What is K-style vs half-round gutters?

K-style (ogee) gutters have a flat back and decorative front profile resembling crown molding. They hold 30% more water than half-round gutters of the same width and are most common on modern homes. Half-round gutters are semicircular, better for historic homes, easier to clean, and less prone to corrosion but require more support brackets.

How do I calculate gutter drainage capacity?

Calculate drainage needed using: Adjusted Roof Area (sq ft × pitch multiplier) × Rainfall Intensity (inches/hour) ÷ 96.23 = GPM (gallons per minute). Then match to gutter capacity: 5" K-style = 92 GPM, 6" K-style = 133 GPM, 5" half-round = 64 GPM, 6" half-round = 96 GPM. Always size up if between sizes.

Gutter Size Calculator

Calculate the right gutter and downspout sizes for your roof. Factor in roof area, pitch, rainfall intensity, and get material recommendations for Myrtle Beach's climate.

Calculate Your Gutter Size

Roof Dimensions

Roof Length (ft)

Roof Width (ft)

Roof Pitch

Rainfall Zone

Intense storms, 50+ inches

Preferred Gutter Style

Gutter Material

Roof Sections (separate drainage areas)

Complex roof with multiple valleys, dormers, or angles

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Enter Your Roof Details

Fill in your roof dimensions and preferences to get personalized gutter sizing recommendations.

Frequently Asked Questions

What size gutters do I need for my home?

Most homes use 5" K-style gutters, which handle roofs up to 2,200 sq ft in moderate rainfall. For larger roofs or heavy rainfall areas like Myrtle Beach, 6" gutters provide extra capacity. Use our calculator above for precise sizing.

How many downspouts do I need?

The general rule is one downspout for every 600 square feet of roof area, with a minimum of two. For areas with heavy rainfall, add 50% more downspouts. Maximum spacing should be 35-40 feet between downspouts.

What's the difference between 5" and 6" gutters?

6" gutters hold 40% more water than 5" gutters. They're recommended for roofs over 2,200 sq ft, steep pitches (8/12+), or areas with intense rainfall. The cost difference is typically 15-25% more for 6" gutters.

Should I get seamless or sectional gutters?

Seamless gutters are custom-made on-site and have fewer leak points, lasting 20-30 years. Sectional gutters are cheaper but joints can separate over time. For coastal climates, seamless aluminum is the best value.

How often should gutters be cleaned?

Clean gutters at least twice yearly: spring and fall. In areas with heavy pine tree coverage, clean every 3 months. After major storms, inspect and clear debris to prevent water damage.

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