Plate-loaded vs selectorized machines: why the numbers differ

Two ways to load a machine

Selectorized: a stack of plates, a pin to choose how many you lift, and cables, pulleys or cams between the stack and the handles. The number is the stacked weight you selected, before any ratio.

Plate-loaded: you add plates to a lever arm or a sled. The arm or sled has its own weight, and where the plates sit on the arm and the angle of the movement decide how much of their weight you actually move.

Why the same number feels different

• Starting resistance: an empty arm or sled already resists, so the plates you load are not the whole load.
• Lever length: plates far from the pivot weigh more on your hands than the same plates near it.
• Pulley ratio: on a stack, a ratio can halve or double what you feel compared with the number.
• Cam profile: a cam makes the resistance change through the rep, differently on each machine.

Starting resistance stated by manufacturers

What the empty plate-loaded machines in our catalog already weigh, according to their manufacturers, quoted word for word with the link and the date. Many are given per arm. Leg presses are in the leg press guide.

Plate-loaded starting weight by brand

Chest press

Shoulder press

Lat pulldown

Seated row

Leg extension

Leg curl

Incline press

Smith machine

How to use the numbers

• Compare a machine with itself over time, not with another brand's number.
• When you switch machine or brand, start lighter and work back up.
• Trust a cross-brand number only where the comparator gives one, with its error band and its confidence level.

Open the comparatorMechanical modelsSafety

How every figure is labelled

MachineConvert never invents a number. Each figure carries one of three levels, with its source link and the date it was read:

Measured

Read on the machine itself with a force gauge, following the measurement protocol, with a proof (continuous video or photos) and the date.

Manufacturer

Quoted word for word from the manufacturer's official page or document, in the units printed there, with the link and the date it was read. A stack weight says what the plates weigh, not what you feel at the handle.

Estimated

Computed from a mechanical model of the machine (lever, cam or pulley) built from sourced inputs. Each estimate shows its method, its error band and a derivation page, and is marked as not verified by measurement.

MethodologyData rules

Related guides

Smith machine bar weight by brand: what the empty bar really weighsPlate-loaded machine starting weight by brand: what the empty machine weighsHow to convert machine weight between gyms and brandsLeg press weight: is what you load what you push?Chest press weight stacks by brand: Technogym vs Life Fitness vs Hammer StrengthLeg extension and leg curl weight by brand: stacks, increments and what the pin means