Elevators, Escalators & Vertical Transport Equipment worked example

Elevator Counterweight Sizing at 110% blocks available for installation: a worked example

What does the result look like when blocks available for installation reaches 110%? The full calculation is worked below with real intermediate numbers. a product engineer or installer needs an early counterweight mass estimate before final balance checks

The inputs for this scenario

  • Counterweight mass per block: 120 lb / block (unchanged)
  • Counterweight blocks planned: 32 blocks (unchanged)
  • Blocks available for installation: 110 % (raised for this scenario; the documented default is 100)
  • Balance acceptance yield: 98 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross counterweight mass = counterweight mass per block × counterweight blocks planned) to the inputs above produces each figure below.
  • At this operating point the engine returns 4,140 lb for usable counterweight mass, the number this scenario is built around.
  • At this operating point the engine returns 3,840 lb for gross counterweight mass.
  • At this operating point the engine returns -384 lb for counterweight mass unavailable.
  • At this operating point the engine returns 84.48 lb for mass held for balance adjustment.

How this compares with the baseline

  • Against the tool's baseline example, where blocks available for installation sits at 100% and the headline result is 3,763 lb, this scenario comes in 10% above the baseline at 4,140 lb.
  • A figure at this level is achievable when blocks available for installation is genuinely sustained, not just peaked for a shift. It sizes total mass only; it does not verify that the blocks physically fit the frame geometry or that the resulting overbalance percentage matches the car weight and rated load, which still requires a balance test.

Results at a glance

  • Usable counterweight mass: 4,140 lb (headline result)
  • Gross counterweight mass: 3,840 lb
  • Counterweight mass unavailable: -384 lb
  • Mass held for balance adjustment: 84.48 lb

Run it with your numbers

  • Every input above is editable in the live Elevator Counterweight Sizing calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.