Lux Meter – Light Meter
Illuminance, EV & foot-candle
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Lux Meter turns your iPhone into a professional light meter. Using your camera and the ISO 2720 photographic standard, it measures illuminance in lux and foot-candles in real time — accurately, fully offline, with no ads and no sign-up.
Whether you're setting up studio lighting, checking your desk for eye comfort, dialing in grow lights for plants, or metering a film scene, Lux Meter gives you the numbers the pros rely on.
MEASURE
• Real-time lux and foot-candle readout (tap to switch units)
• Exposure Value (EV) at your chosen ISO
• Color temperature (CCT in Kelvin) estimate from the camera
• Live camera preview with a center spot reticle
• Spot metering (center) or average metering (whole frame)
• Min / max / average statistics with a live chart
• Hold to lock a reading
• Plain-language light labels (Office lighting, Overcast day, Direct sunlight…)
• Low-light path reads down to sub-1 lux
EXPOSURE CALCULATOR (2-in-1)
• Set any two of aperture / shutter / ISO — it solves the third
• Cinema mode: frame-rate and shutter-angle presets, plus the 180° rule
• ND filter and exposure compensation
• Sunny 16 helper and a depth-of-field estimate
TARGETS & PRESETS
• Use-case presets: Reading, Office/Ergonomics, Photography, Film/Video, Plants & Greenhouse, Aquarium/Terrarium
• Set a target lux band and get a subtle alert when the light is in range
• Optional haptic and audio meter tick that speeds up as light increases
CALIBRATION YOU CAN TRUST
• Independent calibration for front and back cameras
• Multi-point calibration fitted across the whole range
• See raw and calibrated values side by side
• Reset to default anytime
SAVE & EXPORT
• Save single readings or record a session over time
• Min/max/average per session, notes and optional location tag
• History list with rename, delete and CSV export (share sheet)
BUILT RIGHT
• Works 100% offline — no account, no tracking, no network
• No ads, nothing locked behind a paywall
• Grid and histogram overlays, screen-brightness pin, keep-awake
• Clean dark-first design, light mode too
• 8 languages with instant in-app switching
A note on accuracy: iOS does not give apps access to the ambient light sensor, so Lux Meter uses camera-based reflective metering (ISO 2720). For best results, calibrate once against a reference and use the same lighting conditions.
Measure light like a pro. Download Lux Meter.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
New: Grow Light meter — turn any reading into PPFD and the Daily Light Integral (DLI) for your plants, with light-source presets and plant-care guidance.
Also: histogram overlay on by default, a clearer lux/foot-candle switch, and refinements.
The developer, Alper Sumer Guc, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Identifiers
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Alper Sumer Guc
- Size
- 1.9 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 7 more
- English, French, German, Japanese, Korean, Portuguese, Simplified Chinese, Spanish
- Age Rating
4+
- 4+
- Copyright
- © 2026 deve.net