It's not possible to specify exactly how much weight a suspension bridge can hold. This is because when the weight-bearing capacity of a suspension bridge is determined, a lot of factors come into consideration including bridge span, cable length, wind loads and active live loads.
One of the most popular suspension bridges in the world is the Golden Gate Bridge of San Francisco. The total length of Golden Gate Bridge is 8,981 feet. Apart from a total dead load of 887,000 tons, this suspension bridge can hold a total live load (moving load) of 4000 pounds per feet. That makes a total of 36 million pounds over the entire span.