Garbage Disposal Installation Cost: New, Replacement, and Wiring

Garbage disposal installation is a quick flat-rate job as a like-for-like replacement, and a larger job as a first-time install that needs an outlet, a switch, and drain-plumbing changes under the sink.

What does garbage disposal installation cost?

Replacing an existing disposal with a compatible unit runs $120 to $300 in labor. Supplying a mid-grade 3/4 HP unit plus install runs $250 to $500. A first-time install adding an outlet, an air switch or wall switch, and reworking the drain runs $400 to $900.

What does a first-time install add?

• Electrical: a switched outlet under the sink, often a new circuit or a tap with a switch
• Drain reconfiguration: a new continuous waste arm, a dishwasher connection, and sometimes a change from a center to an offset drain
• A basket-strainer removal and mounting-flange install on the sink
• An air switch through the countertop or a wall switch if no outlet-switch is wanted

What should you check before quoting a replacement?

Mounting-collar compatibility (some brands share a mount, some do not), whether the dishwasher drains through the disposal, and the condition of the existing outlet and switch. A photo under the sink answers most of it.

What belongs in the estimate?

The unit and horsepower, mounting hardware, the drain and dishwasher connections, electrical work if any, haul-away of the old unit, and a leak and function test. Note that if the sink flange is corroded or the drain layout is non-standard, additional parts and time apply at a stated rate.