Marked containers
Use a 250 ml cup, 1 l bottle or 2 l jug with visible scale marks.
Free maths tool
Capacity tool
A free classroom capacity model for filling marked containers and connecting millilitres, litres and fullness.
Amount controls
Increase or decrease the fill amount with simple stepper buttons.
Two units
Switch between millilitres and litres while the same container stays visible.
Live labels
Read amount, capacity, amount left and percentage full as the model changes.
What the tool does
The capacity tool gives teachers and students an open model for reading and comparing filled containers.
- choose a cup, bottle or jug
- fill the container by changing the amount
- switch between millilitres and litres
- read the amount, total capacity, amount left and percentage full
- use empty, half, full and random controls for quick examples
How teachers use it
Open it on a classroom display when students need to connect a marked container with capacity language and unit conversions.
- set a fill amount and ask students to read the scale
- switch from millilitres to litres and discuss the same amount in a larger unit
- use half full to connect fractions, percentages and capacity
- ask students to predict the amount left before checking the label
Why it is useful
Capacity work asks students to read a scale, name the unit and reason about the space left in a container. A shared model makes each part visible.
- supports millilitre and litre vocabulary
- connects full, half full, amount and amount left
- works as a model before independent measurement practice
Frequently Asked Questions
Is the capacity tool free?
Yes. Teachers, students and families can open the capacity tool in a browser for free.
Which containers are included?
The tool includes a 250 ml cup, a 1 l bottle and a 2 l jug.
Can it show litres and millilitres?
Yes. The tool can show amounts in millilitres or litres while keeping the same container visible.
Is this different from the measurement practice app?
Yes. The capacity tool is an open model for exploring containers and units, while the measurement practice app gives students practice questions.