How to Install Under-Cabinet Lighting

Use a tape measure to record the length of each cabinet section that will receive lighting, measuring along the front edge of the underside where the strip will be mounted. Write down every measurement and add them together to get the total strip length needed — then add 10% for cutting waste. Decide where the power supply will plug in and trace the cable path back from that outlet to the first strip section. If your countertop has a dark surface (granite, dark quartz), warmer light (3000K) looks best; lighter countertops pair well with 4000K neutral white.

Unbox all components and lay them out on the countertop. Connect the LED strip to the power adapter and dimmer, then plug it into an outlet. Turn the strip on and check for dead spots, color inconsistencies, or flickering along the full length. Test the dimmer across its full range from bright to low. This five-minute test catches defective products before you commit adhesive to your cabinets — returns are much easier when nothing has been cut or mounted yet.

Dampen a clean cloth with rubbing alcohol (isopropyl 90% or higher) and wipe the entire underside front edge of each cabinet where the strips or channels will mount. Kitchen cabinets accumulate a film of cooking grease and dust that prevents adhesive from bonding properly — this is the number one reason strips fall down within weeks. Wipe in one direction, flip the cloth to a clean side, and make a second pass. Let the surface dry completely for at least two minutes before proceeding.

Cut the aluminum LED channel to match each cabinet section length using a hacksaw or the scissors that came with the channel. Peel the adhesive backing from the channel and press it firmly along the front edge of the cabinet underside, about 1 inch back from the front lip — this setback prevents the light from shining directly into your eyes when standing at the counter. Use a level to keep the channel straight. Hold firm pressure for 30 seconds on each section. For extra security on textured surfaces, add a small screw at each end of the channel.

Unroll the LED strip and find the copper cut marks — they appear every 1-2 inches and are usually marked with a scissors icon or dotted line. Measure carefully, find the nearest cut mark to your desired length, and cut straight across with scissors. Peel the adhesive backing from the strip and press it firmly into the aluminum channel (or directly onto the cabinet if skipping the channel). Start from the end nearest the power supply and work outward, pressing firmly every few inches to ensure full contact. If the strip needs to turn a corner or bridge a gap, use a solderless strip-to-strip connector — just slide the exposed copper pads into the connector clips and snap it closed.

If your installation spans multiple cabinet sections, connect each strip segment using solderless connectors — match the positive (+) and negative (−) markings on the strip to the connector. Run the extension wires along the back wall of the cabinet interior or through a small hole drilled in the cabinet side panel with a 1/4-inch bit. Connect the first strip's input end to the dimmer, then the dimmer to the power adapter. Route the power cable along the least visible path toward your outlet — inside the cabinet, along the wall behind the backsplash, or through a cable raceway.

If you installed aluminum channels, snap the frosted diffuser covers into the channel grooves along the full length. The diffuser eliminates visible LED "dots" and blends the light into a smooth, continuous glow — this single step makes the difference between a cheap-looking install and a professional one. Press the cover in starting from one end, working along the channel until it clicks in fully. Trim the diffuser to length with scissors if it extends past the channel.