Math.ceil() Round up
Last updated: 2026-09-09
Math.ceil() Round up
Math.ceil rounds up to the smallest integer >= the given number.
| Category | Math |
|---|---|
| ES version | ES1 |
📝 Syntax
Math.ceil(number);⚙️ Parameters
| number | The number. |
|---|
Returns：The rounded-up integer.
Mutates the original：No (returns a new value)
▶ Example
Edit the code, press Run, and see the result in the output panel:
Output：
5
5
4
-4💡 Tip Pagination: Math.ceil(totalCount / pageSize).
ℹ️ info ceil/floor/round/trunc: up/down/nearest/toward-zero.
🌐 Browser support
| Browser |  Chrome |
 Edge |
 Firefox |
 Safari |
 Opera |
|---|---|---|---|---|---|
| Math.ceil() | ✓ v1 | ✓ v12 | ✓ v1 | ✓ v1 | ✓ v1 |
| Supported by all modern browsers | |||||
🏷️ Related Items
💡 Related Cases
More case studies coming soon — check back later.
📚 Related Tutorials
❓ FAQ
QWhy is Math.ceil(-4.2) -4?
ACeiling goes toward +infinity — -4 > -4.2.
Qceil vs floor vs round vs trunc?
Aceil=up, floor=down, round=nearest, trunc=toward zero.
QHow to calculate total pages?
AMath.ceil(totalCount / pageSize).
