Formulas, without the guesswork.
Choose a relationship from the measurements you know. The variable names below belong to each calculator; a letter can have a different role in another method. π is evaluated using the browser’s full numerical constant, rather than replacing it with 3.14.
Radius and height
Inputs: Radius r (length units); Height h (length units).
Volume and height
Inputs: Volume V (cubic units); Height h (length units).
Volume and radius
Inputs: Volume V (cubic units); Radius r (length units).
Total surface area and radius
Inputs: Total surface area S (square units); Radius r (length units).
Reading the notation
√ means a square root, ∛ means a cube root, and a superscript ² or ³ means a square or cube. Sine, cosine and tangent use angles converted from entered degrees. Where an inverse trigonometric function is used, its displayed angle is converted back to degrees. The ellipse perimeter is approximate; other formula labels describe the ideal mathematical model.
Total surface area here includes two bases. Slanted cylinders and open containers need different surface models.
Reference reading: Right circular cylinder at Wolfram MathWorld.