How much does the biggest rocket weigh?

A rocket's mass on the pad says less about its structure than about its tanks. Starship, the largest vehicle SpaceX has built, weighs close to 5,000 t at liftoff, but the dry mass of the Super Heavy booster and the upper stage together is on the order of 300 t. The rest is propellant: roughly 3,400 t in the booster and 1,200 t in the ship, split between liquid methane and liquid oxygen. That ratio is typical of orbital launchers, which must carry enough energy to reach about 7.8 km/s (28,000 km/h) while fighting gravity and air drag during the first minutes of flight.

The Saturn V weighed about 2,970 t (6.5 million lb) fuelled, with a first stage that alone held some 2,000 t of kerosene and oxygen. NASA's Space Launch System is lighter at roughly 2,600 t, because its solid boosters and hydrogen-fuelled core pack more energy per tonne than kerosene. The Soviet N1 came in at about 2,750 t, the Space Shuttle stack at 2,030 t and SpaceX's Falcon Heavy, the heaviest rocket in regular commercial use, at about 1,420 t. Weighing a rocket is done indirectly: engineers calculate mass from propellant loading sensors and structural measurements, since no scale under the launch mount could handle it.

Liftoff thrust must exceed weight by a comfortable margin. Starship's 33 Raptor engines produce about 74 MN, giving a thrust-to-weight ratio near 1.5 at ignition; Saturn V lifted off at about 1.2. That figure is why very heavy rockets accelerate slowly at first and why every extra tonne of structure costs several tonnes of propellant, which is the central trade-off in launch vehicle design.