Lux Meter

Put light into numbers.

Lux Meter light-level reading
Get it onGoogle PlayComing soonApp Store

Free to download.

See the light at a desk, a plant or a photo subject using your phone’s light sensor. Compare positions, watch changes over time and save readings with charts, notes and media. Use Meter for live light, Tools for extra measurements, Saved for records and Settings for preferences. Use the website walkthrough below to plan a first measurement, then practise with the app’s own controls. Available on Google Play for Android. Hardware, permissions and the feature labels in the installed app determine which functions you can use.

Put it to work.

Practical ways to use Lux Meter.

Compare work areas

Read illuminance where the task happens and compare positions without changing the phone’s orientation.

Explore plant light

Measure at leaf height and choose the light source and hours for plant-light estimates.

Record a lighting change

Start a log or light-map walk, add markers and review the result with its saved context.

Your first few minutes.

Start with a useful task, then keep the result.

Read every step ›

  1. Keep the sensor clear

    Use Find the sensor, then keep your fingers, case and shadow away from it.

  2. Choose the task

    Pick Room, Plants or Photo and set the relevant place, source, hours or ISO.

  3. Compare or keep a reading

    Hold a steady reading or start a deliberate log; Stop saves a completed log to Saved.

Learn by trying.

Settings › Tour & lessons opens the Tour, Showroom and Lessons. Lessons use the live sensor without keeping logs, readings or settings. Start with the website walkthrough, then try a lesson on your phone.

Open the guided walkthrough ›

Practice 1

Is there enough light to work?

Lay the phone where you work, screen up: the sensor sits on its top edge. Pick the place and it says whether the light is enough.

Practice 2

Will the basil grow here?

Hold the phone at leaf height. Pick the light source and its hours: you get the plant light, the light it gathers a day, and a verdict.

Practice 3

Set the camera by the light

Hold the phone at your subject, top edge to the camera. Set the ISO and the aperture; the shutter speed follows.

Small tips. Better results.

Useful habits for your next task.

All tips in the guide ›

Use Find the sensor first and keep fingers, a case edge and your own shadow clear of it.

For a workspace, measure where the work is done, with the phone in the same orientation each time.

For plants, measure at leaf height and select the actual light source and its hours before comparing daily-light estimates.

For incident-light photo readings, hold the sensor at the subject rather than at the camera.

If you have a trusted lux meter, place both in the same light and calibrate the phone against it.

Mark a log when a lamp switches on or the position changes so the chart explains what happened.

Get the highlights.

Take a closer look.

Learn how to use it.

Step-by-step instructions for the app and its tools.

Read the guide ›All videos ›

Get the app

Lux Meter

Free to download. Coming soon to iPhone.

Get it onGoogle PlayComing soonApp Store
How to use Lux Meter ›