Front brake pads generally can go about 30,000 miles before they need to be changed. Because front brake pads take more of the weight when a car stops, the rear brake pads may last twice as long, or about 60,000 miles.
Heavier cars wear through brake pads faster than lighter cars. In addition, aggressive drivers who brake frequently and from high speeds will wear through brake pads faster than cautious drivers. Cautious drivers of light cars may get twice as many miles out of their brake pads.
Change your brake pads when their thickness is down to 1/4 to 1/8 of an inch. On average, front brake pads should be replaced around 30,000 miles and rear brake pads around 60,000, but other factors such as type of car and driving habits affect brake pad life.