For a domestic kitchen faucet, what is the recommended size for the fixture supply pipe?

For a domestic kitchen faucet, the recommended size for the fixture supply pipe is generally 1/2 inch. This size provides an adequate flow rate and pressure for most kitchen sinks while allowing for easy installation and compatibility with standard plumbing fittings. A 1/2 inch supply pipe can accommodate the demands of contemporary kitchen faucets, which often require higher flow rates for tasks like filling pots quickly or operating pull-out sprayers.

Choosing a supply pipe that is too small, such as 1/4 inch, may lead to inadequate water flow, making it difficult to operate the faucet efficiently. Conversely, while larger pipe sizes like 3/4 inch could theoretically provide more flow, they are often unnecessary for the typical usage of a kitchen faucet and can complicate installation and increase costs. A 5/8 inch supply pipe also would not be a common standard size for residential plumbing applications. Thus, 1/2 inch is the most suitable and widely accepted size for domestic kitchen faucet supply lines.