How to Measure a Room With Your Phone Browser
No tape measure. No app download. Just Chrome on Android and your phone's camera — using augmented reality.
What You Need
- An Android phone from 2019 or later (most mid-range and flagship phones qualify)
- Chrome browser version 81+ (already installed on most Android phones)
- Good lighting — natural daylight or a well-lit room works best
- A textured floor (carpet, tiles, or wood) for fastest surface detection
No Play Store download, no account, no subscription. Open the page and measure.
Step-by-Step: Measuring a Room
Open Online AR Ruler in Chrome
Go to onlinearruler.pages.dev in Chrome on your Android phone. Tap "Start AR Measurement." When Chrome asks for camera permission, tap Allow. Your camera feed is processed entirely on your device — nothing is uploaded anywhere.
Scan the floor until the reticle appears
Slowly pan your phone camera across the floor. A glowing ring called the reticle appears when ARCore detects a flat surface. This usually takes 2–5 seconds. Good texture (carpet, tile grout, wood grain) speeds this up.
Walk to the first wall corner
Move to one corner of the room. Position the reticle where the floor meets the wall. Tap the + button to anchor Point 1 to the real-world floor position.
Walk to the opposite wall and tap Point 2
Walk across the room to the opposite wall corner. Keep your phone pointing at the floor. Tap + to place Point 2. The room length displays instantly — in centimetres, millimetres, inches, or feet depending on your unit setting.
Measure width, then record your numbers
Reset and repeat for the room width. Screenshot both measurements. For an L-shaped room, break it into two rectangles, measure each, and add the areas. The Area mode (tap 3+ corner points) does this automatically.
Tips for the Most Accurate Measurements
- Use a textured floor. ARCore works best on carpet, tile, or wood. Smooth white concrete or glass reduces accuracy.
- Keep the phone steady when tapping measurement points. Movement during the tap adds variance.
- Measure within 3 metres for best accuracy. For larger rooms, measure in two 3-metre passes and add the distances.
- Good lighting matters. Open the curtains or switch on the ceiling light — dim conditions reduce depth detection.
- On iPhone? Use the reference calibration mode: place a credit card (85.6mm wide) in frame, tap its edges, and then measure any surface on the same plane.
Common Questions
What phones can measure a room without a tape measure in the browser? +
Any Android phone released after 2019 that supports Google ARCore works in full AR mode. This includes Samsung Galaxy S/A series (2019+), Google Pixel (3a+), OnePlus 7+, Xiaomi Mi 9+, and most mid-range Android phones. iPhones can use the reference calibration fallback mode.
How accurate is measuring a room with a phone browser? +
On a flat, textured floor with good lighting, Online AR Ruler is typically accurate within 1–3 cm for distances under 3 metres. This is precise enough for flooring quotes, furniture planning, and paint area estimation.
Can I measure room area (square metres / square feet)? +
Yes — switch to Area mode. Tap corner points around the room perimeter and the app calculates total area and perimeter automatically. Switch between square metres and square feet at any time.