Rectangle Calculator
MATHCalculate area, perimeter, and diagonal of a rectangle.
ℹ️ About Rectangle Calculator
Rectangle Calculator is a free online math tool from Tools Coaster. Calculate area, perimeter, and diagonal of a rectangle. It is handy for rectangle, area, geometry tasks. It runs entirely in your browser — no sign-up, no installs, and nothing you enter ever leaves your device.
📖 How to Use Rectangle Calculator
1
Enter your numbers
Type the value(s) or sequence you want to work with.
2
Run Rectangle Calculator
The computation runs instantly with full precision.
3
Read the result
See the answer, and the working where the tool shows it.
4
Copy the output
Copy results for your homework, report, or spreadsheet.
💡 Examples
Example calculation
INPUT
Your number(s)→
OUTPUT
Result from Rectangle Calculator🚀 Pro Tips
✓For very large or very small numbers, results may appear in scientific notation.
✓Use it to verify work you did by hand, not just to replace it.
✓Everything runs locally in your browser — your input is never uploaded to a server, so it is safe for private or sensitive data.
✓Combine with the statistics and converter tools for multi-step problems.
✓Bookmark it for quick reference during study sessions.