A fictional calculation example demonstrates why the simple average of different m²/h values can distort cleaning planning.
Oldenburg, 8. October 2026. Anyone consolidating cleaning services for different room groups requires a common time reference. Simply forming an average from two area performance values can lead to an incorrect total duration. The following specialist article from Jonas Gebäudereinigung explains the calculation method for clients and managers of commercial buildings. It builds upon the existing public Jonas methodology; no new product launch is associated with this.
The Jonas resource defines m²/h as the cleaned reference area per productive person-hour. This means the productive person-time of a room group is derived from its area divided by the associated performance value. For multiple groups, these times are calculated first and then added together. Prerequisites are clearly defined areas, the same cleaning pass under consideration, and comparably defined performance values.
A deliberately simplified, entirely fictional example makes the difference visible: Group A comprises 100 m²; for the calculation assumption, 100 m² per productive person-hour apply. This results in 60 person-minutes. Group B also comprises 100 m²; assumed are 300 m² per productive person-hour. This results in 20 person-minutes. Together, this amounts to 80 productive person-minutes for 200 m².
Anyone who instead calculates the arithmetic mean of the two performance values receives 200 m²/h. If one divides the total area of 200 m² by this average, the result is only 60 person-minutes. The model underestimates the time calculated individually before by 20 minutes. The total value matching the correct time, on the other hand, is 150 m² per productive person-hour: 200 m² divided by 80/60 person-hours.
Generally, the calculation method is: total person-time = sum of areas per group divided by their performance value. A consolidated performance value only emerges afterwards from total area divided by total person-time. The figures in the example are arbitrarily chosen. They represent neither measured Jonas performance nor specific room types, industry benchmarks, client premises, or quoted prices.
The time definition must also be correct. Setup times, travel times, and ancillary times must not be missing or double-counted unnoticed. If cleaning intervals differ, clients must first determine which groups are actually being processed in the pass under consideration. If multiple activities are calculated for the same area, these must remain identifiable as separate performance items; the area cannot then be used arbitrarily as a one-off total area.
A verifiable initial table
For the application, a table with a clearly named group, demarcated area, associated performance value, and the resulting calculated person-time is sufficient to begin with. Before summing, each row should show which pass and which activities it applies to. A missing performance value remains visible as an open assumption; it must not be replaced by the average of other groups. After actual execution, planned and documented person-times can be compared separately. This provides a comprehensible basis for queries without turning the model into a promised performance.
Productive person-time is also not a promised duration for an operation. How tasks can be distributed among several people depends on the workflow and conditions at the premises. The calculation therefore replaces neither the determination of the scope of services nor a site-specific examination. For a comparison of offers, however, it makes visible whether areas, performance values, and time estimates fit together in a comprehensible way.
The existing methodology with definitions, limits, and versioned downloads is publicly accessible:
Public Jonas working aid
About Jonas Gebäudereinigung
Jonas Gebäudereinigung, based in Oldenburg, provides commercial cleaning services for business clients. The company provides publicly accessible working aids for the classification and description of cleaning services.
Press contact
Jonas Gebäudereinigung
Julius Harpstedt, Managing Director
Alexanderstraße 101 B
26121 Oldenburg, Germany
Phone: 0441 24923021
Email: info@jonas-gebäudereinigung.de
Website: Jonas Gebäudereinigung
Editorial note: This specialist article was created with AI assistance based on the aforementioned public Jonas working aid and the explicitly described explanation.