How to calculate aspect ratio in Photoshop?

Method 1 - Check existing image:

1. Open your image in Photoshop
2. Go to Image → Image Size
3. Note the width and height (e.g., 1920×1080)
4. Divide width by height: 1920 ÷ 1080 = 1.78 (or 16:9)

Method 2 - Crop to specific ratio:

1. Select the Crop Tool (C)
2. In the top options bar, click the aspect ratio dropdown
3. Choose a preset (16:9, 4:3, 1:1) or enter custom values (e.g., "16:9")
4. Drag to crop your image to that ratio

Method 3 - Create new document:

1. File → New
2. Enter width and height (e.g., 1920×1080)
3. Photoshop maintains the ratio automatically if you lock proportions

For 16:9:

• Set crop to 1920 x 1080 (or 16 x 9)
• Works for any size maintaining that ratio

For Instagram 1:1:

• Set crop to 1080 x 1080 (or 1 x 1)
• Perfect square

For 4:5 (Instagram portrait):

• Set crop to 1080 x 1350 (or 4 x 5)

• ✅Lock the aspect ratio by clicking the link icon between width/height fields
• ✅Use "Constrain Proportions" when resizing to maintain aspect ratio
• ✅The Info panel (F8) shows current dimensions in real-time
• ✅Hold Shift while resizing to maintain proportions
• ✅Use Content-Aware Scale (Edit → Content-Aware Scale) to resize without distortion

Width ÷ Height = Aspect Ratio

• 1920 ÷ 1080 = 1.78 (16:9)
• 1080 ÷ 1080 = 1.0 (1:1)
• 1080 ÷ 1350 = 0.8 (4:5)