Radius of a Cylinder Calculator
Given the height of a right circular cylinder and one other measurement — volume, lateral surface area, or total surface area — this calculator finds the base radius, diameter, and all remaining cylinder properties.
Solve radius from
units
cu units
Radius of the circular cross-section of the cylinder
r = 3.162
- 1
Divide V by πh
314.16 ÷ (π × 10) = 10.000023 - 2
Radius = √(V / (πh))
√10.000023 = 3.1623
How does this calculator work?
Cylinder radius from volume: r = √(V/(πh)). From lateral surface area: r = A_lat/(2πh). From total surface area: solve 2πr² + 2πrh − A = 0. Enter height plus one of these measurements, and all cylinder dimensions (diameter, volume, lateral and total area) are immediately computed.
Formula
How this is calculated
A right circular cylinder has two independent measurements: the base radius r and the height h. The volume is V = πr²h; the lateral (curved) surface area is A_lat = 2πrh; the total surface area adds both circular caps: A_total = 2πr² + 2πrh.
When the volume and height are known, r = √(V/(πh)) is a direct square-root formula. When the lateral surface area and height are known, r = A_lat/(2πh) is a simple linear inversion. When the total surface area and height are known, expanding gives a quadratic in r: 2πr² + 2πrh − A_total = 0, solved by the quadratic formula with the positive root retained.
All formulas assume a perfect right circular cylinder (flat, parallel, circular bases). Enter the height and one measurement in consistent units; the radius and height share the same unit, volume is that unit cubed, and surface areas are that unit squared.
Frequently asked questions
The lateral surface area (A_lat = 2πrh) covers only the curved side of the cylinder, as if you unrolled it into a flat rectangle. The total surface area (A_total = 2πr² + 2πrh) also includes both circular end caps (each with area πr²).
The total surface area formula A = 2πr² + 2πrh contains r², so rearranging for r yields a degree-2 polynomial. The quadratic formula gives two roots; only the positive one is geometrically meaningful.
Rearrange V = πr²h to h = V/(πr²). This calculator solves for radius given height; for other combinations use a full cylinder calculator that accepts any two of the three measurements as inputs.
Also known as
TG we-Calculate Editorial Team. (2026). Radius of a Cylinder Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/radius-of-cylinder-calculator
TG we-Calculate Editorial Team. "Radius of a Cylinder Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/radius-of-cylinder-calculator.
TG we-Calculate Editorial Team, "Radius of a Cylinder Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/radius-of-cylinder-calculator
@misc{wecalculate_radius_of_cylinder_calculator, title = {Radius of a Cylinder Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/radius-of-cylinder-calculator}}, year = {2026}, note = {TG we-Calculate} }
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