📠Aspect Ratio Calculator
Know a video's width but need the matching height for the same proportions? Enter dimensions or use a common ratio such as 16:9 to calculate matching sizes without manually working through the ratio math.
Calculate Aspect Ratio
Enter the width and height of an image, video or screen to find its simplified aspect ratio.
Calculate Matching Dimensions
Choose an aspect ratio and enter either a known width or known height. ToolStrive will calculate the matching dimension.
What Is Aspect Ratio?
Aspect ratio describes the proportional relationship between the width and height of an image, video, display or other rectangular area.
It is commonly written as two numbers separated by a colon, such as 16:9, 4:3 or 1:1.
For example, 1920 × 1080 simplifies to 16:9 because both dimensions can be divided by 120.
How to Use the Aspect Ratio Calculator
Find an Existing Ratio
Enter the width and height of your image or video and click Calculate Ratio. The tool simplifies the two numbers to their smallest whole-number ratio.
Calculate a New Height
Select or enter your desired ratio, enter a Known Width and click Calculate Height.
Calculate a New Width
Select or enter your desired ratio, enter a Known Height and click Calculate Width.
Common Aspect Ratios
| Ratio | Example Dimensions | Common Use |
|---|---|---|
| 16:9 | 1920 × 1080 | Widescreen video and displays |
| 4:3 | 1600 × 1200 | Traditional displays and images |
| 1:1 | 1080 × 1080 | Square images |
| 9:16 | 1080 × 1920 | Vertical video |
| 3:2 | 1500 × 1000 | Photography |
Aspect Ratio Formulas
Calculate Height
Height = Width × Ratio Height ÷ Ratio Width
For example, with a 16:9 ratio and a width of 1280:
1280 × 9 ÷ 16 = 720
Calculate Width
Width = Height × Ratio Width ÷ Ratio Height
For example, with a 16:9 ratio and a height of 1080:
1080 × 16 ÷ 9 = 1920
Aspect Ratio and File Format
Aspect ratio describes width-to-height proportions and does not determine whether a file is JPG, PNG or WebP. If the proportions are already correct but you need another file type, use the Image Format Converter.
Frequently Asked Questions
How do I calculate the aspect ratio of an image or video?
Enter the width and height. The calculator simplifies those dimensions to a width-to-height ratio using their greatest common divisor.
How do I find the height for a 16:9 image?
Choose or enter a 16:9 ratio and provide the known width. The calculator uses the ratio to determine the matching height.
Can I use aspect ratios for print dimensions?
Yes. Aspect ratio is a proportion, so the same calculation can be used with pixels, inches, centimeters or other consistent units.