LED Lighting Calculator by Space
Calculate how many luminaires you need for each room. Enter your data and instantly obtain the total lumens.
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💡 What are Lux and Lumens?
Lumens (lm) measure the total amount of light emitted by a light source. It is the "flow" of light coming from a bulb.
Lux (lx) measures how much light reaches a surface. 1 lux = 1 lumen/m². It is the "density" of light at a point.
Example: An 800 lm bulb illuminates a 2 m² table with 400 lux. The same bulb in 20 m² only provides 40 lux.
📐 Practical Calculation of Lumens
The practical formula to calculate the total required lumens:
Example kitchen 10 m²:
500 lm/m² × 10 m² = 5,000 lm
The lm/m² recommended depends on the type of area: from 100 lm/m² in outdoor areas and garages up to 1,000 lm/m² in operating rooms. Our calculator automatically applies the appropriate value according to the selected space.
📊 Recommended Lumens per m² by Area
| Area | lm/m² | Typical Use |
|---|---|---|
| Outdoor / Garden | 100 | Landscape lighting |
| Garage | 100 | Parking |
| Bedroom | 200 | Relaxed atmosphere, occasional reading |
| Storage | 300 | Storage and logistics |
| Hallway | 300 | Safe transit |
| Restaurant | 300 | Cozy atmosphere |
| Living Room / Lounge | 300 | Comfortable general lighting |
| Museum | 300 | Artwork viewing |
| Classroom | 500 | Reading and studying |
| Bathroom | 500 | Personal grooming, mirror |
| Kitchen | 500 | Safe food preparation |
| Office | 500 | Work with screens and documents |
| Store / Retail | 500 | Product display |
| Workshop / Industry | 750 | Precision manual work |
| Operating Room | 1000 | Surgery, maximum visibility |
Frequently Asked Questions about LED Lighting
We address the most common questions about lumens, lux, and luminaire calculations
What are lumens and why do they matter more than watts?
Lumens (lm) measure the total amount of visible light emitted by a light source. Unlike watts, which measure electrical consumption, lumens tell you how much actual light you get.
With LED technology, a bulb of just 10 W can produce the same 800 lumens as a 60 W incandescent bulb. That’s why, when purchasing LED lighting, you should always look at lumens: they are the true indicator of brightness.
Tip: Use our calculator to find out exactly how many lumens you need for your space.
How many lumens per square meter do I need?
It depends on the type of room. As a practical reference:
Living room → 300 lm/m²
Kitchen / Office → 500 lm/m²
Industrial workshop → 750 lm/m²
The calculation is straightforward: multiply the recommended lm/m² by the area of your space. For example, a 10 m² kitchen requires 500 × 10 = 5,000 total lumens. Our calculator performs this operation automatically.
What is the equivalence between lumens and watts in LED?
The luminous efficacy of current LEDs is between 100 and 140 lm/W. As a practical reference for equivalence:
Incandescent 60 W ≈ LED 8 W → ~800 lm
Incandescent 75 W ≈ LED 11 W → ~1100 lm
Incandescent 100 W ≈ LED 14 W → ~1600 lm
Our calculator uses an efficacy of 120 lm/W as a standard value to estimate the total power of the installation, a representative figure for current high-quality LED technology.
How many lumens and LED downlights do I need for a kitchen?
The kitchen requires 500 lm/m², as it is a workspace where food and sharp utensils are handled. For a typical 10 m² kitchen, you need 5,000 total lumens (500 × 10).
With 1,200 lm LED downlights, you would need about 4–5 units distributed evenly. If you use higher-power LED panels (3,000–4,000 lm), 1 or 2 units will suffice. Supplement with LED strips under the upper cabinets to illuminate the countertop.
Use the calculator by selecting “Kitchen — 500 lm/m²” and enter your kitchen’s exact measurements for a precise result.
Are 1,200 lumens enough to light a room?
It depends on the size of the room and its use. A 1,600 lm luminaire is equivalent to an incandescent bulb of about 100 W and produces sufficient light for a bedroom of 8 m² (200 lm/m² × 8 = 1,600 lm) or a hallway of 5 m² (300 lm/m² × 5 = 1,500 lm).
However, for a 20 m² living room, you would need several 1,200 lm luminaires (about 5 units) to reach the recommended 6,000 lm (300 lm/m² × 20). For kitchens or offices, the number would be somewhat higher due to the 500 lm/m² required.
Select 1,200 lm in the calculator chips to see how many units you need for your specific space.
How do I calculate how many lumens I need in total?
The calculation is simple and straightforward:
Where lm/m² depends on the type of room (200 for bedrooms, 300 for living rooms, 500 for kitchens/offices/bathrooms, etc.) and the area is the length times the width of your space in square meters.
Our calculator applies this formula automatically: you just need to select the type of room and enter the dimensions. It will provide the total lumens and the exact number of fixtures according to the wattage you choose.
What is the difference between warm, neutral, and cool light?
The difference lies in the color temperature, measured in degrees Kelvin (K):
Neutral (4,000–4,500 K) → Natural white, balanced
Cool (5,000–6,500 K) → Bluish white, stimulating
Warm light is ideal for bedrooms, living rooms, and restaurants because it creates a relaxed atmosphere. Neutral works well in bathrooms, kitchens, and retail spaces. Cool is recommended for offices, workshops, and work areas where maximum concentration is required. Color temperature does not affect lumens: a 1,200 lm bulb provides the same illumination in warm or cool.
How many lumens do I need for a bathroom?
A bathroom requires 500 lm/m². For a standard 5 m² bathroom, this means 2,500 total lumens (500 × 5). Two downlights of 1,200 lm each or a ceiling fixture of 2,500 lm is sufficient.
Keep in mind that the bathroom is a humid area: you need fixtures with at least IP44 protection (IP65 if installed directly above the shower or bathtub). Additionally, supplement with a LED wall light next to the mirror of about 600–800 lm in neutral tone (4,000 K) for personal grooming.
What is a lux and how does it differ from a lumen?
Lux (lx) measures the amount of light that reaches a surface, while lumen (lm) measures the total amount of light emitted by a source. The relationship is direct: 1 lux = 1 lumen per square meter.
Think of it like a water hose: lumens are the flow rate coming out, and lux are how much water falls per square meter on the ground. The same hose (same lumens) wets more if you aim at a small area (more lux) than if you water a large area (less lux). That's why, when calculating lighting, it's not enough to know the lumens of the bulbs: you need to know the surface area of the space.
Does ceiling height affect lighting?
Yes, the ceiling height affects how the light is distributed, although the calculation of total lumens is based on the surface area of the space (length × width). The higher the ceiling, the more the light disperses before reaching the work plane.
For standard ceilings (2.5–3 m), the recommended lm/m² values work directly. In high ceilings (over 4 m), such as industrial warehouses or commercial premises, it is advisable to use luminaires with more focused optics (such as LED high bays) to direct the light downward and avoid losses. Our calculator takes ceiling height into account to show you the optimal distribution of luminaires.