Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Ideal Euclidean geometry. Use one consistent length unit. Measurements and derived quantities use floating-point arithmetic. Simple polygons without holes; concave polygons are supported. Crossing or nonadjacent touching edges are rejected. Near-degenerate geometry is rejected with a relative tolerance.
Example Calculation
- Ordered vertices: x, y: 0, 0; 4, 0; 4, 3; 0, 3
The rectangle (0,0), (4,0), (4,3), (0,3) has area 12 and centroid (2,1.5).
Frequently asked questions
How do I use this calculator?
Enter ordered vertices: x, y. The result updates automatically. Use Reset to restore the example values.
What method does it use?
2A_signed=Σ(xᵢyᵢ₊₁−xᵢ₊₁yᵢ); centroid uses cross-product weighted endpoint sums.. Ideal Euclidean geometry. Use one consistent length unit. Measurements and derived quantities use floating-point arithmetic. Simple polygons without holes; concave polygons are supported. Crossing or nonadjacent touching edges are rejected. Near-degenerate geometry is rejected with a relative tolerance.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.