Belt size decides who can run
A 55-inch belt suits walkers and runners under about 5 ft 8 in. If you're taller, or you run faster than 8 mph, get a 60-inch belt. Width matters less until you're tired: 20 inches is fine, and 22 inches is more forgiving when your stride starts to wander late in a run.
Belt size sets the footprint too. Every 60-inch machine on our list is at least 76 inches long open, and the safety standard asks for 20 inches clear on each side and 78 inches behind the deck. That's a lot of room. If you don't have it, our compact treadmills page is the place to start.
Look for continuous horsepower
Budget treadmills often advertise peak horsepower, which is what the motor can hit for a moment. Continuous horsepower (CHP) is what it can hold for an hour. For walking, 2.0 CHP is plenty. A runner under 180 lb is well served by 2.5 to 3.0, and heavier runners or anyone logging daily miles should look at 3.5 and up. Our treadmill motors explained page covers why a big peak number on the sticker doesn't tell you much.
Incline is the feature you'll use most
Most people buy a treadmill for speed and end up using it for incline. A 10% grade turns a walk into a real workout without the impact, and 12 to 15% is what the 12-3-30 routine calls for. Decline, on some NordicTrack and Bowflex machines, is nice for trail runners, but it isn't worth paying extra for if you don't run hills.
Noise depends on the room as much as the machine
Motor hum is rarely what bothers the people downstairs. It's the thud of each foot strike, and that depends on the deck cushioning and what the machine stands on. A 6 mm rubber mat and a ground-floor room solve most complaints. Our walking pad noise test page lays out how we're measuring it.
Decide on a subscription before you buy the screen
A lot of treadmill touchscreens come with a monthly bill, and some lose most of their use when you stop paying. If you want trainer-led classes, NordicTrack and Peloton do them best, and the subscription is part of the real price. If you don't, buy a Sole or Horizon with a simple console and a tablet shelf, and put the money into the deck and motor.
