How do I calculate pixel dimensions from aspect ratio?

Before using the formulas, convert your aspect ratio to a decimal number:

• 16:9 = 16 ÷ 9 = 1.778
• 4:3 = 4 ÷ 3 = 1.333
• 21:9 = 21 ÷ 9 = 2.333
• 1.85:1 = 1.85
• 9:16 = 9 ÷ 16 = 0.5625

Example 1: Find Height from Width (16:9)

You have: 1920 pixels width

Target ratio: 16:9 (1.778 as decimal)

Calculation: 1920 ÷ 1.778 = 1080 pixels

Result: 1920 x 1080 pixels

Example 2: Find Width from Height (4:3)

You have: 1080 pixels height

Target ratio: 4:3 (1.333 as decimal)

Calculation: 1080 × 1.333 = 1440 pixels

Result: 1440 x 1080 pixels

Example 3: Vertical Video (9:16)

You have: 1080 pixels width

Target ratio: 9:16 (0.5625 as decimal)

Calculation: 1080 ÷ 0.5625 = 1920 pixels

Result: 1080 x 1920 pixels (vertical format)

Step 1: Choose Your Starting Point

• Enter known width OR height
• Leave the other field blank

Step 2: Select Aspect Ratio

• Pick from common presets (16:9, 4:3, etc.)
• Or enter custom ratio

Step 3: Get Instant Results

• Calculator shows both dimensions
• Guaranteed to maintain exact ratio
• No manual math needed

Video Production:

Need 4K resolution at 16:9?

• Known: 3840 width
• Calculate: 3840 ÷ 1.778 = 2160 height
• Result: 3840 x 2160 pixels

Social Media Graphics:

Instagram post at 4:5?

• Known: 1080 width
• Convert 4:5 to decimal: 0.8
• Calculate: 1080 ÷ 0.8 = 1350 height
• Result: 1080 x 1350 pixels

Web Design:

Hero image at 21:9 ultrawide?

• Known: 2560 height
• Convert 21:9 to decimal: 2.333
• Calculate: 2560 × 2.333 = 5972 width (round to 6000)
• Result: 6000 x 2560 pixels

Photography Print:

8x10 print from 3:2 camera?

• Camera ratio: 3:2 (1.5)
• Print ratio: 10:8 (1.25)
• Ratios don't match - cropping needed
• Either crop to 1.25 or accept borders

Always Round to Even Numbers:

Video codecs work best with even pixel counts:

• ✅1920 x 1080 (both even)
• ✅1280 x 720 (both even)
• ❌1921 x 1081 (odd numbers cause issues)

Standard Resolutions:

When possible, use established standards:

• 1920 x 1080 instead of custom 16:9
• 3840 x 2160 for 4K
• 1280 x 720 for HD

These work better across devices and platforms.

Pixel Perfect vs. Close Enough:

For professional video: Must be exact

For web graphics: Can round slightly

For print: DPI matters more than exact pixels

YouTube Videos:

• Stick to 16:9 ratio
• Use 1920 x 1080 minimum
• 3840 x 2160 for 4K upload

Instagram Feed:

• Square: 1080 x 1080 (1:1)
• Portrait: 1080 x 1350 (4:5)
• Landscape: 1080 x 566 (1.91:1)

TikTok/Reels:

• Always 9:16 vertical
• 1080 x 1920 standard
• Full screen mobile experience

Cinematic Content:

• 2.39:1 for ultra-wide
• 1920 x 803 (from 1080 height)
• 3840 x 1607 (from 4K height)

To Find Height:

1. Enter your width in pixels
2. Select or enter aspect ratio
3. Calculator shows height automatically

To Find Width:

1. Enter your height in pixels
2. Select or enter aspect ratio
3. Calculator shows width automatically

To Find Both from Resolution:

1. Select common resolution preset
2. See both dimensions immediately
3. Aspect ratio calculated automatically

• ✅Use our calculator to avoid rounding errors
• ✅Save common dimensions as presets
• ✅Verify calculations before rendering
• ✅Round to nearest even number for video
• ✅Check platform requirements first

• ❌Don't guess dimensions manually
• ❌Don't use odd pixel counts for video
• ❌Don't ignore platform specifications
• ❌Don't forget to maintain aspect ratio