Math
PI function: calculate circle area, pipe circumference, and tank volume
Use full 15-digit precision PI() instead of hardcoded 3.14 for engineering areas, circumferences, and cylindrical volumes.
Avoid rounding drift from hardcoded 3.14
Typing 3.14 introduces a 0.05% systematic error that compounds on large storage tanks and pipe runs. PI() takes zero arguments (keep the empty parentheses) and returns 3.14159265358979.
For a cylindrical tank of radius r = 2.5 m and fill height h = 4 m, volume PI() * r^2 * h equals 78.54 cubic meters (whereas 3.14 * 2.5^2 * 4 understates volume at 78.50 m³—about 39.8 liters off before rounding).
| RadiusM (A) | HeightM (B) | Floor Area (m²) | Volume (m³) |
|---|---|---|---|
| 2.5 | 4 | 19.635 | 78.54 |
Compute tank volume and circumference
PI() * A2^2 * B2 computes cylinder volume, while 2 * PI() * A2 computes outer circumference (15.708 m).
=ROUND(PI() * A2^2 * B2, 2)Zero radius boundary
When radius is 0, both cross-sectional area and volume evaluate cleanly to 0.
=ROUND(2 * PI() * A2, 4)Try the example
Use the original values or change them to test your understanding.