How long your brakes will last depends on a number of factors like driving in urban areas or mostly highway, distance driving.
There is usually no clear-cut schedule that tells you when it’s time to replace the brakes, so you need to rely on your ears and the advice of an experienced automotive technician. Most vehicles should have their tires rotated at least every six months, and that is a good time to have the brakes inspected, as well. A mechanic can check the thickness of the pads and the condition of the calipers or drum hardware to spot wear.
Many cars have built-in wear sensors that scrape against a brake disc when the pads needed replacing. The driver will hear a screeching sound when the brakes are used. Those sensors aren’t on every car so drivers should listen for squeaking, squealing, metal-on-metal grinding or other noises that indicate wear. Some minor noises can be eliminated by cleaning the brakes, but persistent, prominent noises usually mean parts are worn. It’s best to rely on regular brake maintenance inspections than to assume the car has your back.