Xiaomi Redmi Note 9: what screen size is a smartphone? Full guide on diagonal, resolution and features of the display

Xiaomi Redmi Note 9 remains one of the most popular models in the budget segment even years after its release. When choosing a smartphone, screen size is a key parameter that affects usability, multimedia capabilities and even ergonomics. But how to understand the numbers? Diagonal in inches, physical dimensions in centimeters, resolution in pixels — all this is easy to confuse, especially if you are first encountering technical specifications.

In this article, we will not only answer the question “what screen size Redmi Note 9 has”, but also understand:

• 📏 Exact display diagonal in inches and centimeters – why manufacturers only specify inches?
• 🔍 Screen resolution and pixel density: how it affects image clarity?
• 📱 Type of matrix and technology: IPS vs AMOLED, refresh rate, brightness.
• 🆚 Comparison with other Redmi models and competitors (Samsung, Realme).
• 🛡️ How to choose a cover or protective glass, knowing the size of the screen?

You’ll also learn some little-known nuances, like why the actual screen area may be different from the one you’re supposed to be, and how to check for broken pixels before you buy it, and if you’re planning to buy a Redmi Note 9 or already own it, that information will help you use your smartphone as efficiently as possible.

1.The exact screen size of Xiaomi Redmi Note 9: diagonal in inches and centimeters

The main question that worries users is how many inches of screen Redmi Note 9? According to official data of the manufacturer, the diagonal of the display is 6.53 inches, this value is indicated in all specifications and marketing materials Xiaomi.

But for many users, centimeters are more familiar. To convert inches to centimeters, we use a factor of 2.54 (1 inch = 2.54 cm).

6.53 inches × 2.54 cm/inch = 16.59 cm

So the Redmi Note 9 screen size in centimeters is 16.59 cm, but there's an important caveat: it's the size of the diagonal, not the width or height of the screen. The actual dimensions of the display (excluding the bezels) are about 15.88 × 7.19 cm.

⚠️ Warning: Don't confuse the screen diagonal with the size of the smartphone body! full dimensions of the Redmi Note 9 — 162.3 × 77.2 × 8.9 mm, which includes frames and back panel.

Why do manufacturers specify size in inches? It's a historically established practice: inches are traditionally used to denote diagonals of electronic devices (TVs, monitors, smartphones). In addition, inches are more convenient for comparing models - for example, the difference between 6.53" and 6.67" is noticeable, whereas in centimeters it is 16.59 cm vs 16.94 cm, which is less obvious.

2. Screen resolution and pixel density: what does this mean for the user?

Diagonal is not the only parameter that determines the quality of the picture. Equally important is the screen resolution, that is, the number of pixels horizontally and vertically. Xiaomi Redmi Note 9 resolution is 2340 × 1080 pixels (Full HD+).

• 📺 2340 pixels horizontally (width).
• 📏 1080 pixels vertically (height).
• 🔄 The aspect ratio is 19.5:9 (an elongated format typical of modern smartphones).

The resolution is directly related to the pixel density (PPI — pixels per inch) — the number of pixels per inch of the screen. For the Redmi Note 9, this figure is ~395 PPI. The higher the PPI, the clearer and more detailed the image.

The pixel density of 395 PPI is a great indicator for a budget smartphone, which means that the human eye does not distinguish individual pixels at a standard reading distance (20-30 cm from the screen), which means that the text, photos and videos on the Redmi Note 9 will look clear and smooth, without grain.

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To check the screen for broken pixels, open a monochromatic image (white, black, red, green, blue background) on your smartphone to full brightness. The broken pixels will be visible as colored dots that do not change shade.

Type of matrix and screen technology: IPS vs AMOLED

Xiaomi Redmi Note 9 is equipped with IPS-In-Plane Switching is the most common technology for budget and mid-range smartphones, and let's look at the pros and cons of it compared to the more expensive ones. AMOLED-screen:

• ✅ Advantages IPS Redmi Note 9: 💡 More natural color reproduction (important for photographers and designers). 🔋 Less power consumption when displaying light colors (e.g. web pages). 💰 Lower cost of production → lower-priced smartphone.
• ❌ Deficiencies IPS: 🌑 Less contrast (black appears gray rather than deep). ☀️ Worse visibility in the sun compared to AMOLED. 📱 Greater screen thickness (AMOLED thinner and more flexible).

Redmi Note 9 is used in the IPS-It's a Sunlight Display-enabled array that automatically adjusts contrast and brightness depending on the lighting. IPS The screen has a maximum brightness of 450 nits, which is enough for comfortable use in most conditions.

Compare it to the competition:

• 📱 Redmi Note 9 Pro — IPS, 450 nits (similar).
• 📱 Samsung Galaxy M31 — AMOLED, 420 nits (best contrast but lower brightness).
• 📱 Realme 6 — IPS, 480 nits (brighter but still) IPS).

⚠️ Note: If you use your smartphone in the bright sun, look for models with a brightness of 500 nits (for example, the Redmi Note 10 Pro with a bright light). AMOLED and 700 nits).

4. Comparison with other Xiaomi models: Which screen is better?

To see how good the Redmi Note 9 screen is, compare it to other popular Xiaomi models in the same price segment.

The table shows that the Redmi Note 9 is inferior to the newer models in two key parameters:

1. Matrix Type: AMOLED in the Redmi Note 10 provides better contrast and energy efficiency.
2. Upgrade Frequency: 120Hz in the Poco X3 NFC and Redmi Note 10 Pro makes animation and scrolling more smooth.

However, for most tasks (social networks, videos, instant messengers) 60 Hz and IPS-The Redmi Note 9 is quite enough, and the 120 Hz difference is only noticeable in games or in fast scrolling. AMOLED It is important for lovers of contrast images (for example, when watching movies with dark scenes).

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If you need a smartphone to play or watch HDR-content, consider the models with AMOLED frequency 90/120 Hz. For everyday tasks IPS and 60 Hz in Redmi Note 9 — best-choice.

5. How does screen size affect the choice of cover and protective glass?

Knowing the exact screen size of the Redmi Note 9, you can choose the right accessories.

• 📏 Screen size: 6.53 inches (16.59 cm).
• 📐 Physical screen sizes (without frames): ~15.88 × 7.19 centimeter.
• 🔄 Side ratio: 19.5:9 (extended format).
• 🖥️ Permission: 2340×1080 (Full HD+).

When choosing a protective glass, pay attention to:

Suitable for a diagonal of 6.53 inches | Has a cutout for the front camera (center) | Covers the entire screen area without gaps | Compatible with an ultrasonic fingerprint sensor (if any) | No more than 0.3 mm thickness (to maintain sensitivity)

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For cases, the dimensions of the case are important, not just the screen.

• 📏 Length: 162.3 mm.
• 📐 Width: 77.2 mm.
• 📌 Thickness: 8.9 mm.
• 🕳️ Connectors: USB-C bottom, 3.5 mm audio jack at the top, double sim + microSD on the right.

⚠️ Warning: Some cheap cases may overlap the proximity sensor or microphone. Check the Redmi Note 9 compatibility reviews before buying. M2003J15SC global version).

If you are planning to use liquid glass or hybrid protection, consider:

• 🔧 Applying coating better in a service center - self-application requires experience.
• 🛡️ Liquid glass does not protect against strong impacts, but prevents mycroscrapies.
• 🔄 Avoid contact with water for 12 to 24 hours.

6. Frequent questions about the Redmi Note 9 screen: FAQ

7.Conclusion: Should you buy the Redmi Note 9 in 2026?

The Xiaomi Redmi Note 9 is still the choice for those looking for a reliable smartphone with a large screen at an affordable price. IPS-Full-resolution display HD+ fit:

• 🎬 Watching videos (including Full) HD on YouTube/Netflix).
• 📖 Reading books and articles (comfortable font size).
• 🎮Casual games (although 120Hz is better for eSports).
• 📸 Viewing photos (good color reproduction for the IPS).

But if you care,

• 🌑 Deep black color and high contrast → Choose models with AMOLED (Redmi Note 10).
• 🔄 Smooth animation → Look for smartphones with 90/120 Hz (Poco) X3, Redmi Note 11 Pro+).
• ☀️ Good visibility in the sun. → Pay attention to the brightness of 500 nits.