How to Use Ruler on iPhone: A Step-by-Step Guide

Measuring things using a ruler is pretty basic, right? But, did you know that your iPhone comes equipped with its very own ruler? That’s right! The next time you find yourself without a physical ruler, your trusty iPhone can come to the rescue. With just a few taps, you can measure objects with surprising accuracy. So, let’s get into it – here’s a quick guide on how to use the ruler on your iPhone.

Step by Step Tutorial on How to Use Ruler on iPhone

Before we dive into the step-by-step tutorial, let’s talk about what we’re trying to achieve. The iPhone’s ruler function is part of the Measure app, which uses augmented reality (AR) to gauge the size of objects. It’s not just a static image of a ruler – it’s a dynamic tool that interacts with the space around you.

Step 1: Open the Measure app

Locate and tap the Measure app icon on your iPhone to open it.

The Measure app is pre-installed on most iPhones, so you won’t need to download anything new. It’s usually found in your Utilities folder or on your home screen if you use it frequently.

Step 2: Follow the on-screen instructions

When you first open the Measure app, you’ll be prompted with on-screen instructions to move your iPhone around.

This helps the app calibrate and understand the space around you. It’s a crucial step to ensure the measurements are as accurate as possible.

Step 3: Point your iPhone camera at the object

Aim your iPhone’s camera at the starting point of the object you want to measure.

Make sure you’re in a well-lit area and that the object’s edges are clear. The more visible the object is, the more accurate your measurement will be.

Step 4: Tap the ‘+’ button to start measuring

Press the ‘+’ button on the screen to set the starting point for your measurement.

You’ll see a virtual white dot appear on the object, indicating where the measurement starts. Ensure this dot is precisely where you want to begin measuring.

Step 5: Move your iPhone to the end point

Slowly move your iPhone to the end point of the object you’re measuring, keeping the device steady.

The app will draw a virtual line as you move, showing the length being measured. Try to keep your movements smooth for the best results.

Step 6: Tap the ‘+’ button to finish measuring

Once you’ve reached the end point, tap the ‘+’ button again to set the final measurement.

You’ll then see the measured length displayed on the screen. If you need to measure another side of the object, just reposition your iPhone and repeat steps 4 through 6.

After you complete these steps, you’ll have a precise measurement of the object in question. Whether you’re sizing up a piece of furniture, checking the dimensions of a frame, or simply satisfying your curiosity, the Measure app on your iPhone is a surprisingly handy tool.

Tips on How to Use Ruler on iPhone

  • Make sure the object you’re measuring is on a flat surface for the best results.
  • If the app has trouble detecting the object, try moving closer or adjusting the lighting in the room.
  • For smaller objects, you can use the Measure app’s built-in level tool for added precision.
  • Remember that the Measure app is best for approximate measurements – for critical tasks, use a physical ruler or tape measure.
  • You can take a photo of your measurement by tapping the shutter button, which is great for keeping a record.

Frequently Asked Questions

How accurate is the iPhone ruler?

The iPhone’s Measure app is quite accurate, but it should be used for approximate measurements rather than precision engineering.

Can the Measure app measure height?

Yes, you can measure an object’s height by measuring from the base upwards.

Does the Measure app work in the dark?

The Measure app requires good lighting to function correctly, so it may not work well in the dark.

Can I measure the distance between two points on a map with the Measure app?

No, the Measure app is designed for measuring physical objects, not distances on a map.

Can the Measure app measure angles?

The Measure app includes a level tool, which can be used to measure angles relative to the ground.


  1. Open the Measure app.
  2. Follow the on-screen instructions to calibrate.
  3. Aim the camera at the object’s starting point.
  4. Tap the ‘+’ button to start measuring.
  5. Move your iPhone to the end point.
  6. Tap the ‘+’ button again to finish measuring.


So, there you have it! Using the ruler on your iPhone is a piece of cake once you get the hang of it. It’s one of those nifty tricks that can save you time and hassle when a physical ruler isn’t on hand. Whether you’re a DIY aficionado, a student, or just someone who loves exploring the myriad of features their iPhone offers, the Measure app’s ruler function is worth getting familiar with. And remember, while it’s handy for quick measurements, it’s not a replacement for professional measuring tools when precision is key. So, the next time you need to size something up, give your iPhone a chance to show off its measuring skills!