Cylinder Circumference Calculator
Find the circumference of a cylinder's circular base, its diameter, base area, and lateral (side) surface area. Enter the radius and optionally the height.
units
units
Perimeter of the circular top or bottom face: C = 2πr
- 1
Radius
5 - 2
Diameter (2r)
2 × 5 = 10 - 3
Base circumference C = π × d
π × 10 = 31.4159Equivalently C = 2πr ≈ 6.2832 × r.
How does this calculator work?
A cylinder's base circumference is C = 2πr (about 6.283 × r). The lateral (curved) surface area is C × h = 2πrh. Enter radius and height and the calculator provides circumference, diameter, base area and lateral surface area instantly.
Formula
How this is calculated
A cylinder's circumference is the perimeter of its circular cross-section — the distance you would measure if you wrapped a tape around the outside of the cylinder. The formula C = 2πr comes directly from the definition of π: the ratio of a circle's circumference to its diameter. Equivalently, C = πd where d = 2r is the diameter.
The lateral (side) surface area is obtained by imagining the curved surface unrolled flat: it becomes a rectangle whose width is the circumference and whose height is the cylinder's height. So lateral area = C × h = 2πrh. This is the formula used to calculate how much material is needed to wrap the curved surface of a can or tube.
All calculations use π ≈ 3.14159265358979 and return results in the same units you enter for the radius (and height). There is no unit conversion built in — be consistent (all in cm, all in inches, etc.).
Frequently asked questions
Use C = π × d. If you know the diameter instead of the radius, enter half the diameter in the radius field (r = d ÷ 2), or simply multiply the diameter by π ≈ 3.14159.
Circumference is a 1-D length — the perimeter of one circular face. Lateral surface area is a 2-D area — the entire curved outer surface of the cylinder. Lateral area = circumference × height = 2πrh.
Yes. For a solid cylinder use the outer radius for the outer circumference. For a hollow pipe or tube, the outer circumference is 2π × outer radius; the inner circumference is 2π × inner radius. This calculator handles one radius at a time.
Also known as
TG we-Calculate Editorial Team. (2026). Cylinder Circumference Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/cylinder-circumference-calculator
TG we-Calculate Editorial Team. "Cylinder Circumference Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/cylinder-circumference-calculator.
TG we-Calculate Editorial Team, "Cylinder Circumference Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/cylinder-circumference-calculator
@misc{wecalculate_cylinder_circumference_calculator, title = {Cylinder Circumference Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/cylinder-circumference-calculator}}, year = {2026}, note = {TG we-Calculate} }
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