How to use this calculator
- Enter or choose i know the.
- Enter or choose value.
- Enter or choose length unit.
- The volume updates as you type. Use Copy result or Share to keep it.
Method
V = ⁴⁄₃πr³; r = d/2 = C/(2π) = √(A/4π); 1 litre = 1,000 cm³
- r
- radius
- d
- diameter
- C
- circumference (round the widest part)
- A
- surface area
Worked example
- r³ = 5³ = 125.
- V = ⁴⁄₃ × π × 125 = 500π/3 ≈ 523.598776 cm³.
- In litres: 523.598776 ÷ 1,000 ≈ 0.5236 L.
A sphere of radius 5 cm has a volume of about 523.6 cm³, a little over half a litre.
What the result means
Volume grows with the cube of the radius: a ball twice as wide holds eight times as much.
Assumptions and limits
- The object is a perfect sphere.
- For capacity, the value is the inside measurement.
- Real balls and tanks have wall thickness; measure the inside radius for capacity.
Questions
How do I measure the radius of a ball?
Wrap a tape round its widest part to get the circumference, then choose Circumference; the radius is C ÷ 2π.
What is the volume of a hemisphere?
Half the sphere: ⅔πr³, shown as the hemisphere volume.