Choosing equipment · 6 min read
Sizing a machine: the calculation we do on every quote
Customers lead with their floor area. The number we actually need is the cleaning window — how many hours the floor is genuinely available — because that is what decides the machine class.
Theoretical versus real productivity
Every machine has a theoretical productivity figure: working width multiplied by travel speed. Real productivity is always lower, because of turning, overlap between passes, obstacles, emptying, refilling and the simple fact that operators slow down where things are tight.
As a planning rule we discount theoretical figures by 30 to 40 per cent in open warehouses, and by 50 per cent or more in racked, congested or heavily obstructed areas. Anyone quoting you a machine off the brochure figure alone is setting you up to run over.
Work backwards from the window
Take the area you must cover, divide by the hours available, and you have the productivity you need in square metres per hour. Then pick the smallest machine that clears that number with the discount applied. Oversizing costs money in hire rates, access problems and manoeuvrability; undersizing costs a shift.
A three-hour night window on 12,000 m² needs roughly 4,000 m² per hour of real productivity — ride-on territory. The same floor with all weekend available is comfortably a walk-behind job.
| Machine class | Indicative real productivity | Typically suits |
|---|---|---|
| Walk-behind sweeper | 1,500–2,500 m²/h | Up to ~2,000 m² per clean; aisles, docks, workshops |
| Compact ride-on sweeper | 3,000–5,000 m²/h | 2,000–10,000 m² open floor, car park levels |
| Large ride-on sweeper | 5,000–9,000 m²/h | Distribution centres, yards, hardstand |
| Walk-behind scrubber | 800–1,800 m²/h | Retail, food, clinics, back-of-house |
| Ride-on scrubber | 2,500–4,500 m²/h | Warehouse and factory floors |
| Road sweeper truck | Kerb kilometres per shift | Roads, estates, site access, hardstand |
The constraints that override the maths
Door widths and aisle widths cap machine size regardless of area. Floor loading limits matter on suspended slabs and mezzanines. Noise limits rule out engine-driven machines in occupied buildings and near residential boundaries at night. Battery run time has to cover the window without a mid-shift charge, or opportunity charging has to be built into the plan.
Bring these up early. They frequently change the answer more than the floor area does.