3㎡ · stairs
360
lm · 120 lux
3 m² stairs — 360 lumens
A room at 120 lux needs 360 lumens. That is 3.6 watts of LED, or 1 bulbs of 800 lumens.
Watts are not brightness
Equal lumens mean equal brightness; what changes is the electricity. An LED makes 100 lumens per watt, a filament 13 — nearly eight times apart. The monthly figure below assumes five hours a day for thirty days.
- LED100 lm/W3.6 W
- fluorescent60 lm/W6 W
- halogen20 lm/W18 W
- incandescent13 lm/W27.7 W
- Light reaching the floor
- 120 lux
- Light you need
- 360 lm
- Room size
- 3 ㎡
- In pyeong
- 0.9
- In 800-lumen bulbs
- 1
- A month of electricity
- 0.5 kWh
- Extra watts if incandescent
- 24 W
Several lamps beat one
The same lumens crammed into one fitting light the spot beneath and leave the corners dark. Splitting them across several 800-lumen lamps softens shadows, and one failure no longer means a dark room.
Nearby cells
Same room, other uses
Same use, other sizes
3㎡ · stairs
360lm
4㎡ · stairs
480lm
5㎡ · stairs
600lm
6㎡ · stairs
720lm
8㎡ · stairs
960lm
10㎡ · stairs
1200lm
12㎡ · stairs
1440lm
15㎡ · stairs
1800lm
17㎡ · stairs
2040lm
20㎡ · stairs
2400lm
23㎡ · stairs
2760lm
26㎡ · stairs
3120lm
30㎡ · stairs
3600lm
33㎡ · stairs
3960lm
40㎡ · stairs
4800lm
45㎡ · stairs
5400lm
50㎡ · stairs
6000lm
60㎡ · stairs
7200lm
70㎡ · stairs
8400lm
80㎡ · stairs
9600lm
How to read this
- The light you need is lux times floor area; the use decides the lux.
- Watts are only that light divided by the lamp’s efficacy — not a measure of brightness.
- Bulb counts round up from one 800-lumen lamp.
- Ceiling height, wall colour and shades are not in this calculation.
Frequently asked questions
Q. How many lumens for a 3 m² stairs?
360 lumens — 120 lux times the floor area.
Q. How many watts should the lamp be?
3.6 W as LED, 6 W as fluorescent. An incandescent would draw 27.7 W — 24 W more.
Q. How many bulbs do I need?
1 at 800 lumens each. Spread them out rather than stacking them in one fitting.
Q. What does it cost to run?
On LED at five hours a day, 0.5 kWh a month.