Surface Area of a Cylinder Formula Explained, With Examples
Every surface area of a cylinder result comes from one formula. Once you understand what goes into it, you can sanity-check any figure you are given, whether by an employer, a bank, a teacher or another website.
The formula
2πr(r + h)
What each input means
- Radius: the value you enter in the calculator.
- Height: the value you enter in the calculator.
Example
For example, with these inputs:
- Radius: 5
- Height: 10
the calculator returns:
- Surface area: 471.2389
How the result changes
The table keeps the other inputs at their example values and changes radius.
| Radius | Surface area |
|---|---|
| 5 | 471.2389 |
| 2.5 | 196.3495 |
| 3.75 | 323.9767 |
| 6.25 | 638.136 |
| 7.5 | 824.6681 |
Why it matters
These calculations come up in school, at work and in daily life, from PSLE and O-Level practice to measuring a room for new flooring. Doing them by hand builds understanding, and a calculator lets you check the answer instantly.
Rounding is a common source of small errors. Keep full precision during intermediate steps and round only the final answer to the number of decimal places or significant figures the question asks for.
Each formula has assumptions built in. Area formulas assume flat shapes, volume formulas assume regular solids and statistical measures assume the data you enter is the data you want to describe. Knowing the assumptions helps you pick the right tool.
A quick mental estimate before calculating is a powerful check. If a room's floor area comes out at 4,000 square metres or a percentage comes out above 100% when it should not, you know to look again.
Related calculations
- Area of a Rectangle Calculator: Calculates the area of a rectangle from the measurements you enter.
- Area of a Square Calculator: Calculates the area of a square from the measurements you enter.
- Area of a Triangle Calculator: Calculates the area of a triangle from the measurements you enter.
- Triangle Area from Three Sides (Heron's Formula): Calculates the triangle area from three sides (heron's formula) from the measurements you enter.
Use the Surface Area of a Cylinder Calculator to plug in your own numbers.
Run your own numbers: Surface Area of a Cylinder Calculator