What are the common sizes of round TFT displays besides 5 inch?

If you're shopping for round TFT displays, you’ve probably noticed that the 5-inch size is a popular sweet spot, especially for applications like smartwatches, dashboard instruments, and portable devices. But the market offers a much wider range of diameters, from tiny 0.96-inch panels to large 10.1-inch ones. Let’s break down the most common sizes you’ll actually find in production, with real data and use cases, so you can pick the right one for your project. One key reference point is the 5 inch 1080x1080 round tft display, which hits a resolution sweet spot for many embedded systems.

1.0 to 1.5 Inches: The Ultra-Compact Segment
These tiny round displays are everywhere in wearables and small IoT devices. The most common sizes are 0.96-inch, 1.1-inch, and 1.28-inch. For example, a 0.96-inch round TFT typically has a resolution of 160x80 or 128x128 pixels, with a pixel density around 150 to 200 PPI. The 1.28-inch variant, often used in smartwatch clones, offers 240x240 resolution at about 265 PPI. These panels usually use SPI or I2C interfaces to save pins, and they consume under 20 mA at full brightness. You’ll find them in fitness trackers, small digital gauges, and even toy displays. The small size keeps cost low—around $3 to $8 per unit in moderate volumes—but the viewing angle is often limited to 120 degrees due to the TN or STN technology used in budget models.

1.5 to 2.0 Inches: The Smartwatch Standard
This range is dominated by 1.54-inch and 1.69-inch round displays. The 1.54-inch size, with a resolution of 240x240 or 360x360, is a direct fit for many smartwatch designs. Pixel density jumps to around 330 PPI for the 360x360 version, which looks sharp even at close viewing distances. The 1.69-inch variant, often found in mid-range smartwatches, pushes resolution to 390x390, giving about 326 PPI. These panels typically use MIPI DSI or QSPI interfaces, with 16-bit or 18-bit color depth. Brightness levels range from 300 to 500 nits, and they include an integrated capacitive touch panel. Power consumption is higher—around 50 to 100 mA—because of the backlight and touch controller. You’ll see these in products like the Amazfit Bip series or custom smartwatch projects. The cost per unit is $10 to $20, depending on whether you need a touch layer or a custom cover glass.

2.0 to 3.0 Inches: The Industrial and Automotive Sweet Spot
Sizes like 2.1-inch, 2.4-inch, and 2.8-inch are common in rugged handheld devices, medical monitors, and automotive dashboards. A 2.1-inch round TFT often has a resolution of 480x480, which gives a square-ish active area but with a circular mask. Pixel density is about 323 PPI. The 2.4-inch version, used in some digital cameras and drone controllers, typically runs at 320x320 or 480x480, with brightness up to 600 nits for outdoor readability. The 2.8-inch round panel is a favorite for aftermarket car gauges, offering 480x480 resolution at 240 PPI. These displays use either MIPI DSI or RGB parallel interfaces, and they often include an optical bonding layer for anti-glare performance. Operating temperature ranges are wider—from -20°C to +70°C—making them suitable for vehicle interiors. Prices range from $15 to $35, with higher costs for high-brightness or wide-temperature versions.

3.0 to 4.0 Inches: The Mid-Range Powerhouse
This segment includes 3.5-inch, 3.9-inch, and 4.0-inch round displays. The 3.5-inch size, with a resolution of 480x480 or 640x640, is popular in smart home hubs and portable gaming devices. Pixel density for the 640x640 version is about 258 PPI, and brightness can reach 800 nits with an IPS panel. The 3.9-inch round TFT, often used in marine instruments or aviation displays, has a resolution of 480x480 or 720x720, with a contrast ratio of 1000:1. These panels typically use MIPI DSI with 4 lanes, supporting 24-bit color. They also include a robust touch controller, either resistive or capacitive, and are often supplied with a pre-bonded cover glass. Power consumption is significant—200 to 400 mA—so you’ll need a dedicated backlight driver. Cost per unit is $25 to $50, with custom cover glass adding $10 to $20 more.

4.0 to 5.0 Inches: The Versatile Workhorse
Besides the 5-inch size, you’ll find 4.0-inch, 4.3-inch, and 4.7-inch round displays. The 4.0-inch round TFT, with a resolution of 480x480 or 720x720, is used in some smart mirrors and point-of-sale terminals. Pixel density is 254 PPI for the 720x720 version. The 4.3-inch size, often seen in industrial control panels, offers 480x480 resolution at 158 PPI, which is lower but still readable for text and icons. The 4.7-inch round variant is a rare but interesting size, typically with 540x540 resolution at 162 PPI. These displays use MIPI DSI or LVDS interfaces, and they support 24-bit color depth. Brightness ranges from 500 to 1000 nits, with an optical bonding option for high ambient light conditions. The 5-inch 1080x1080 round TFT is a standout here because it offers a full HD resolution in a circular format, which is rare. For comparison, a 4.0-inch 720x720 panel has about 518,400 pixels, while the 5-inch 1080x1080 has 1,166,400 pixels—more than double. This makes the 5-inch size ideal for applications requiring detailed graphics, such as medical imaging or advanced dashboards. Prices for 4.0 to 4.7-inch panels range from $30 to $60, while the 5-inch version with MIPI HX8399 driver can cost $45 to $70, depending on quantity and touch options.

5.0 to 7.0 Inches: The Large Format Segment
Sizes like 5.5-inch, 6.0-inch, and 7.0-inch round displays are less common but still available from specialized manufacturers. The 5.5-inch round TFT often has a resolution of 720x720 or 1080x1080, with pixel density around 196 PPI for the 720x720 version. The 6.0-inch size, used in some digital signage or kiosk applications, typically offers 720x720 resolution at 170 PPI. The 7.0-inch round panel is the largest you’ll find in standard production, with a resolution of 1024x1024 or 1280x1280, giving about 206 PPI. These panels use LVDS or eDP interfaces, with 8-bit color depth and brightness up to 1000 nits. They often include a multi-touch capacitive touch panel and an anti-reflective coating. Power consumption is high—500 to 800 mA—so thermal management is important. Cost per unit is $60 to $120, with custom cover glass and bonding adding $20 to $40. These are used in high-end automotive clusters, marine navigation systems, and interactive museum displays.

7.0 Inches and Above: The Niche Giant
Above 7 inches, round TFT displays become very rare and expensive. You might find a 8.0-inch or 10.1-inch round panel, but these are typically custom orders from manufacturers like Innolux or BOE. The 10.1-inch round display, for example, might have a resolution of 1920x1920, giving about 272 PPI, but the cost can exceed $200 per unit. These are used in specialized industrial equipment, such as radar screens or large format portable monitors. The interface is usually LVDS or eDP with 8-bit or 10-bit color depth. Brightness is often 800 to 1200 nits, and the operating temperature range is -30°C to +80°C. Because of the low volume, lead times can be 8 to 12 weeks, and you’ll need to negotiate directly with the manufacturer.

Key Technical Specifications Across Sizes
To help you compare, here’s a table of common round TFT sizes with typical specs:

| Size (inches) | Typical Resolution | Pixel Density (PPI) | Interface | Brightness (nits) | Common Use Case |
|---------------|-------------------|---------------------|-----------|------------------|-----------------|
| 0.96 | 160x80 | 150 | SPI | 200 | Fitness tracker |
| 1.28 | 240x240 | 265 | SPI | 300 | Smartwatch |
| 1.54 | 360x360 | 330 | MIPI DSI | 400 | Smartwatch |
| 2.1 | 480x480 | 323 | MIPI DSI | 500 | Handheld device |
| 2.8 | 480x480 | 240 | RGB | 600 | Car gauge |
| 3.5 | 640x640 | 258 | MIPI DSI | 800 | Smart home hub |
| 4.0 | 720x720 | 254 | MIPI DSI | 800 | Smart mirror |
| 5.0 | 1080x1080 | 305 | MIPI DSI | 800 | Dashboard |
| 6.0 | 720x720 | 170 | LVDS | 600 | Digital signage |
| 7.0 | 1280x1280 | 206 | eDP | 1000 | Marine display |

Interface and Driver Considerations
The interface choice is critical for round TFTs. Smaller sizes (under 2 inches) often use SPI or I2C because they need fewer pins and lower power. For example, a 1.28-inch 240x240 panel with SPI can run at 40 MHz, giving a refresh rate of about 30 Hz. For sizes 2 to 4 inches, MIPI DSI with 1 or 2 lanes is common, supporting 60 Hz refresh at 480x480 resolution. The 5-inch 1080x1080 round TFT uses MIPI DSI with 4 lanes and a dedicated driver like the HX8399, which can handle the high pixel clock of about 60 MHz. For sizes above 5 inches, LVDS or eDP is preferred because they support higher resolutions and longer cable runs. The driver IC is often integrated into the panel, but you need to check compatibility with your microcontroller; for example, the HX8399 is common for 5-inch panels, while the ILI9341 is used for smaller ones.

Optical Performance and Bonding
Optical bonding is a key factor for outdoor or high-vibration applications. Many round TFTs in the 3 to 7-inch range come with optical bonding, which reduces glare and improves contrast. For instance, a 5-inch 1080x1080 panel with optical bonding can achieve a contrast ratio of 1200:1 in direct sunlight, compared to 800:1 without bonding. The bonding process uses a liquid optically clear adhesive (LOCA) that fills the air gap between the LCD and cover glass. This adds about 0.5 mm to the thickness and increases cost by $10 to $20. For smaller sizes under 2 inches, bonding is rarely used because the cost-to-benefit ratio is low.

Power Consumption Patterns
Power consumption scales with size and brightness. A 0.96-inch round TFT at 200 nits consumes about 15 mA from a 3.3V supply, or 50 mW. A 2.8-inch panel at 600 nits draws about 80 mA, or 264 mW. The 5-inch 1080x1080 panel at 800 nits can draw 200 mA, or 660 mW, with the backlight accounting for 70% of the power. For battery-powered devices, you’ll need to consider PWM dimming or dynamic backlight control. Some panels support low-power modes like sleep mode, which reduces consumption to under 1 mA. Always check the datasheet for the exact power profile, as it varies by manufacturer.

Mechanical and Mounting Details
Round TFTs have a circular active area, but the outer bezel is often square or rectangular. For example, a 1.54-inch round display might have a square outline of 30x30 mm, with the circular active area centered. The 5-inch 1080x1080 round TFT typically has a square outline of 110x110 mm, with a circular active area of 108 mm diameter. You need to account for the bezel in your enclosure design. Most panels come with a flexible flat cable (FFC) that has a 0.5 mm pitch, with 30 to 50 pins depending on the interface. For mounting, you can use adhesive tape or screw holes, but check the datasheet for the recommended method. The thickness of the panel plus backlight is usually 2.5 to 4.5 mm, with the cover glass adding 0.5 to 1.0 mm.

Availability and Lead Times
Standard sizes like 1.28-inch, 1.54-inch, 2.1-inch, and 3.5-inch are widely available from distributors like Mouser, Digi-Key, or direct from manufacturers like DisplayModule. Lead times are 2 to 4 weeks for stock items. Larger sizes, like 5.5-inch or 7.0-inch, often have longer lead times of 4 to 8 weeks because they are made to order. Custom sizes, like 8.0-inch or 10.1-inch, may require a minimum order quantity of 100 to 500 units and lead times of 8 to 12 weeks. The 5-inch 1080x1080 round TFT is a relatively new size, so availability is good from specialized suppliers, but it’s worth checking stock levels before starting a design.

Cost Breakdown by Volume
Pricing varies significantly by volume. For a 1.28-inch round TFT, unit cost is $5 to $8 at 100 units, dropping to $3 to $5 at 1000 units. A 2.8-inch panel costs $15 to $20 at 100 units, and $10 to $15 at 1000 units. The 5-inch 1080x1080 round TFT costs $45 to $60 at 100 units, and $35 to $45 at 1000 units. For 7-inch panels, expect $80 to $120 at 100 units, and $60 to $90 at 1000 units. These prices include the LCD, backlight, and driver IC, but not the touch panel or cover glass. Adding a capacitive touch panel adds $5 to $20, depending on size and features.

Real-World Application Examples
In the smartwatch market, the 1.54-inch 360x360 round TFT is the most common size, used in devices like the Huawei Watch GT series. For industrial handhelds, the 2.1-inch 480x480 panel is popular because it fits in a rugged housing while offering good readability. In automotive aftermarket, the 2.8-inch 480x480 round TFT is used for boost gauges and tire pressure monitors. The 5-inch 1080x1080 round TFT is finding its way into high-end motorcycle dashboards and portable medical monitors, where the high resolution allows for detailed graphs and maps. For marine applications, the 7.0-inch 1280x1280 panel is used in chart plotters and fish finders, where the large size and high brightness are essential for outdoor use.

Future Trends in Round TFT Sizes
The market is moving toward higher resolutions and larger sizes. We’re seeing 1.5-inch panels with 390x390 resolution, and 2.1-inch panels with 720x720. The 5-inch 1080x1080 size is a step toward 4K round displays, but that’s still a few years away for mainstream production. Also, flexible round TFTs are emerging, with sizes like 1.5-inch and 2.0-inch, but they are more expensive and have lower yield rates. For most projects, sticking with standard sizes like 1.28-inch, 2.1-inch, 3.5-inch, or 5-inch gives you the best balance of cost, availability, and performance.