When designing buildings, carrying out renovations and preparing engineering solutions, it is important to know in advance what lighting a room will need. Too little light reduces comfort and safety; too much means extra luminaires in the estimate and overpaying for electricity every month. That is why we built an online room lighting calculator — a tool for quick preliminary assessment that our engineers use and that is now available to everyone.
💡 Open the lighting calculator →
What the calculator calculates
- The standard illuminance for the selected room type — according to SN RK 2.04-01-2011 "Natural and artificial lighting";
- the required luminous flux in lumens to meet the standard;
- the power consumption of the lighting system in watts and the specific power per m²;
- the current in a 220 V network — for preliminary selection of circuit breakers and cable cross-section;
- the number of luminaires — for six typical models at once: LED panels, lamps, floodlights.
The result can be printed or saved as a PDF and attached to the technical specification.
What data you need
The calculator includes more than 30 room types in seven groups: housing, offices, educational and medical institutions, retail and catering, production and warehouses, common areas. In addition to the type, specify:
- Area The floor area of the room in m² — according to the measured plan or technical passport.
- Ceiling height The higher the mounting height, the greater the light loss: a workshop with an 8 m ceiling will need noticeably more luminaires than an office of the same area.
- Wall and ceiling colour Light surfaces reflect up to 70% of light, dark ones several times less.
- Lamp type LED, fluorescent, halogen or incandescent — this determines the luminous efficacy and the resulting power.
How the calculation is performed
The luminous flux method is used — the same one used in design practice at the concept stage:
Φ = E × S × Km × ν / η
where E is the illuminance standard, lx; S is the area, m²; Km is the maintenance (safety) factor (1.2 for housing and offices, up to 1.5 for production); ν is the non-uniformity factor; η is the luminous flux utilisation factor.
Then the power: P = Φ / luminous efficacy of the lamps, the current: I = P / 220 V, and the number of luminaires is the luminous flux divided by the flux of one luminaire, rounded up.
Example A 50 m² office, a standard of 300 lx, light finishes, LED. The required flux will be around 20–30 thousand lm — that is approximately 6–8 LED panels of 36–40 W (about 3.5–4 thousand lm each), a total power of about 0.22–0.32 kW and a current of around 1–1.5 A. The figures are approximate: the exact result depends on the coefficients entered.
Illuminance standards — guidelines
| Room | Standard, lx |
|---|---|
| Bedroom / living room | 100 / 150 |
| Kitchen | 200 |
| General-purpose office | 300 |
| Design office, laboratory | 500 |
| Classroom, lecture hall | 400 |
| Sales floor | 300 |
| Precision work shop | 750 |
| Enclosed warehouse / with active operations | 75 / 150 |
Luminous efficacy of lamps — why LED pays off
Different lamps produce the same luminous flux at very different power levels. That is exactly why the choice of lamp type has the greatest impact on the electricity bill.
| Lamp type | Luminous efficacy, lm/W (typically) | Service life, approximate |
|---|---|---|
| Incandescent | 10–15 | about 1,000 h |
| Halogen | 15–25 | 2,000–4,000 h |
| Fluorescent | 50–80 | 8,000–15,000 h |
| Light-emitting diode (LED) | 90–150 | 25,000–50,000 h |
Why an online calculation is convenient
A manual calculation requires knowledge of standards and coefficients. The calculator does it in a minute and lets you compare scenarios: LED versus fluorescent lamps, light finishes versus dark, 40 W panels versus 60 W. In a single 2,000 m² warehouse, the difference between options amounts to dozens of luminaires and hundreds of thousands of tenge a year in electricity.
Tip Calculate the same property in two or three variants and save a PDF of each. This makes it easier to justify the choice of equipment to management or to compare commercial offers from luminaire suppliers.
Typical mistakes when choosing lighting
Attention The mistakes we see most often on site:
- calculating "in watts" per metre rather than in lumens — modern LED luminaires of the same power can differ in luminous flux by a factor of one and a half;
- forgetting the maintenance factor: lamps lose brightness over time and diffusers get dirty;
- not taking mounting height into account in warehouses and workshops;
- choosing cable cross-section and circuit breakers without calculating the current — this risks overheating the line;
- installing the same lighting in all areas, although workstations need one standard and walkways another.
When you need a professional design
The calculator provides a preliminary guideline. Working documentation (the EO and EM sections — electric lighting and electrical equipment), state expert review and commissioning require a lighting calculation that takes into account the room geometry, room index, the actual efficiency of luminaires and the reflectance of all surfaces. This work is carried out by our design department — together with equipment selection, diagrams and installation.
- the project undergoes state expert review or is commissioned with the participation of GASK (State Architectural and Construction Control);
- production and warehouse premises with high ceilings;
- emergency and evacuation lighting;
- outdoor lighting of grounds, facades and car parks;
- an energy audit and upgrade of an existing lighting system.
Lighting costs can be reduced not only through lamps: combined with solar panels and occupancy sensors, electricity costs for warehouses and workshops drop noticeably.
Calculate lighting online · Order an electric lighting design · Calculate the cost of construction
Need a complete lighting design? Send us your calculation result or a floor plan — an engineer will prepare the design, select the equipment and estimate the installation.
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