Detailed Answer
The two gutter profiles dominate residential installations in Sacramento, and each has genuine strengths depending on the application.
K-style gutters (also called ogee gutters) are the current industry standard. Their flat back mounts flush against the fascia board for a clean installation, and the decorative front profile resembles crown molding. The profile also gives K-style gutters more water capacity per inch of width than half-round — a 5-inch K-style gutter handles approximately 1.4x the volume of a 5-inch half-round. This capacity advantage is the reason K-style dominates in newer construction and is the default choice for homes with significant roof drainage area.
Half-round gutters are a simple semicircular trough. The smooth interior curve has no flat bottom or corners where debris compacts, which means leaves and debris slide out more readily. Plumbers and gutter cleaners generally find half-round easier to flush clean. Half-round gutters suit older Sacramento architecture — bungalows, craftsman homes, and historic properties in Land Park and Curtis Park — where the traditional profile fits the architectural period better than the more modern K-style ogee.
Capacity comparison: for the same width, K-style holds roughly 40% more water volume. On steep roofs or homes with long gutter runs, this difference matters during high-intensity rain. Half-round gutters on these homes typically need to be oversized — 6-inch half-round to match the performance of 5-inch K-style.
Cost is comparable between the two profiles at equivalent widths. Half-round fittings (end caps, inside corners, outside corners) can be slightly more expensive because they're less common and require round-profile accessories. Guard options are also more limited for half-round, though half-round micro-mesh guards are available from professional suppliers.