Checked example
Worked calculation
Result: At depth y = r, the circular segment is a semicircle, so any level horizontal tank is exactly 50% full.
01 • Guide
Orientation changes partial volume
Full capacity is independent of orientation. Partial capacity is not: a horizontal tank fills slowly near the curved bottom, fastest around the middle and slowly again near the top.
Keep the full precision of intermediate values and round only the final display. This avoids compounding error when a derived radius or converted unit is used in another step.
02 • Guide
What depth means
Measure liquid depth vertically from the lowest inside point. It must lie from zero to twice the internal radius. Tank tilt, dished ends and internal baffles are outside this ideal cylindrical model.
The calculator validates physical limits before displaying a result. Blank or impossible inputs never produce a stale value, NaN or Infinity.
03 • Guide
Operational safety
Treat this as a geometry estimate, not a certified gauge. Fuel expansion, freeboard, calibration tables and regulatory limits may require a lower allowable fill. Follow the tank maker’s documentation.
Interpretation
How to use the result responsibly
The answer models an ideal geometric cylinder. Manufacturing tolerances, wall thickness, rounded ends, deformation, tank tilt and measurement uncertainty can all shift a real value. Use inside dimensions for capacity and outside dimensions for occupied space. For safety, compliance, dosing, structural or purchasing decisions, compare the estimate with drawings, calibration data or a qualified professional.
Dimensional checks help catch mistakes: a volume result must carry cubic units, an area result square units and a derived radius or height linear units. If changing one unit alters the represented physical size, a conversion step was missed.