Window Light Estimator
Pick a window direction and how far back the pot sits. You get an estimated lux range, the light category it falls in, and the houseplants that suit it.
Window
Estimated light
Direct
20,000 to 60,000 lux
Sun landing on the spot itself.
Low
0 to 2500 lux
Medium
2500 to 10000 lux
Bright Indirect
10000 to 20000 lux
Direct
Above 20000 lux
This is an estimate, not a measurement. Direction, obstruction and
distance are the three biggest factors, so a rough answer is possible from them alone.
Roof overhangs, wall colour, glass coatings, your latitude and the weather on the day
all move the number, which is why the result is a wide range rather than a figure.
To find out what a spot really gets, measure it with
Solspot.
Plants that suit this spot
Stop guessing and measure it
Solspot reads the spot in lux through your camera's exposure meter, names the light category with the honest range attached, and matches it against all 100 species here. Free, offline, no account.
Common Questions
How much light does a north facing window get?
In the northern hemisphere a north facing window is the dimmest aspect, because it never gets direct sun. Right at the glass on a clear summer day it usually lands somewhere around 2,000 to 6,000 lux, which is Low to Medium light. In winter it can drop below 1,500. In the southern hemisphere the same is true of south facing windows instead.
What does bright indirect light actually mean in lux?
Roughly 10,000 to 20,000 lux: right at an unobstructed window, without sun falling on the leaves. It is much rarer indoors than the phrase suggests. A spot that looks bright to you is often only 2,000 to 5,000 lux, because your eyes adapt to indoor light and a meter does not. More on what the phrase means.
How accurate is estimating light from window direction?
It is a rough guide. The three inputs here are the biggest factors, but overhangs, wall colour, glass coatings, latitude and the weather all shift the result, which is why the answer is a range and a category rather than a number. The category is the part to act on.
Why does light drop so fast away from the window?
Indoor light falls off quickly with distance. One metre back often gets about half what the sill gets, and two metres back can be under a third. That is why a plant that is fine on the sill slowly declines on a shelf across the room, even though the room still looks bright to you.
Does a net curtain make much difference?
More than most people expect. A sheer or net curtain typically cuts light by around 40 percent, and frosted or textured glass by around half. That is often enough to move a spot down a whole category, from Bright Indirect to Medium.
More plant tools:
Plant Light Requirements ·
Pet-Safe Plant Checker