Basics and units
Volume of a kettle or vessel
Measure the diameter and the height, and the tool gives the litres. Measure the height of the liquid, and it gives the volume left in the vessel.
Result
Fill in the values and run the calculation, or try the example.
This is the calculation Krausi uses. Create an account to save it in a recipe or a brew.
Create my accountWhy calculate the volume of your kettle?
A kettle sold as “50 L” rarely holds 50 usable litres: depending on the manufacturer, it is the volume to the brim or a rounded figure. Knowing the real volume of your vessel lets you plan water volumes without a boil-over.
The same calculation is used to mark the vessel. By entering a height of 1 cm, you get the litres per centimetre: then a stainless ruler, or marks engraved on the mash paddle, is all you need to read a volume mid-brew without transferring anything.
It is a calculation to do once, when your equipment arrives, and to note in your equipment settings.
How is the volume of a vessel calculated?
The volume of a cylinder is the area of the base multiplied by the height:
V (L) = π × (diameter / 2)² × height / 1000with the inside diameter and height in centimetres. For a kettle 40 cm in diameter, each centimetre of height is 1.26 L.
Measure inside the vessel, not outside: on a double-walled vessel, the difference reaches several litres.
Worked example
Values entered
- Inside diameter in cm: 40
- Inside height (or liquid height) in cm: 50
Result from the tool
- Volume in litres
- 62.83 L
What the tool does not do
- The calculation applies to cylinders: it does not account for a domed or conical bottom.
- It gives the geometric volume, not the usable volume: keep some headroom for the boil.
- The expansion of hot metal is ignored.
Frequently asked questions
How many litres per centimetre in my kettle?
Enter your diameter and a height of 1 cm. A kettle 40 cm in diameter holds 1.26 L per centimetre; a 30 cm kettle, 0.71 L.
What kettle size for 20 L of beer?
Allow at least 30% of headroom above the pre-boil volume. For 20 L in the fermenter, you boil about 25 L: a 33 to 36 L kettle avoids boil-overs. The brew water volumes calculation gives the exact pre-boil volume.
And with the assistant?
Ask Krausi the same question in plain language: he picks this tool, does the calculation and files the result in your project.
My new kettle is 40 cm in diameter and 50 cm high, how much does it hold?
It holds 62.83 L to the brim, which is 1.26 L per centimetre of height. I'm noting these dimensions in your equipment settings.