At the default root font size of 16px, 4.5rem is exactly 72px.
Calculation based on a root font-size of 16 pixels.
How to convert 4.5rem to px
To convert rem to pixels, multiply the rem value by the root font size: px = rem × 16. For 4.5rem that is 4.5 × 16 = 72px.
72px is a large size, common for headings, section padding and generous layout gaps.
4.5rem at different root font sizes
| Root font size | Input | Result |
|---|---|---|
| 10px | 4.5rem | 45px |
| 12px | 4.5rem | 54px |
| 14px | 4.5rem | 63px |
| 15px | 4.5rem | 67.5px |
| 16px | 4.5rem | 72px |
| 18px | 4.5rem | 81px |
| 20px | 4.5rem | 90px |
| 22px | 4.5rem | 99px |
| 24px | 4.5rem | 108px |
CSS examples
font-size: 4.5rem; /* 72px */
padding: 4.5rem;
margin-bottom: 4.5rem;
width: 4.5rem;The same values in pixels, if you need a fixed size:
font-size: 72px;
padding: 72px;Tailwind CSS equivalent
As a font size, 4.5rem is the default text-7xl class.
Nearby values
Frequently Asked Questions
4.5rem equals 72px when the root font size is the browser default of 16px. The calculation is 4.5 × 16 = 72.
72px equals 4.5rem at a 16px root font size (72 ÷ 16 = 4.5).
Yes. rem is relative to the root font size, so 4.5rem becomes 81px at an 18px root and 90px at a 20px root. Use the base font size field above to try any value.
Prefer rem for font sizes, spacing and layout so they respect the user's browser font settings and scale for accessibility. Use px for details that should never scale, such as 1px borders or fixed icon sizes.