Resources For Teachers For Tutors For Students & Parents Pricing
Create Free Account
Year 3 Maths Volume & Capacity

Measure capacity in litres & millilitres

20 practice questions 0 video lessons Theory + worked examples
Practice 20 questions
Practice questions

Every question with a fully worked solution.

Start practising
Create a free accountTrack your progress and save your work as you go.
Create free account

Theory

Measuring capacity in litres and millilitres is a Year 3 measurement skill: capacity is how much a container can hold, measured in litres (L) and millilitres (mL). This Year 3 maths page explains the fact that 1 L = 1000 mL, how to read a measuring jug scale, how to choose the right unit, and how to change between litres and millilitres. Curriculum: VC2M3M02 / AC9M3M02.

Capacity is how much liquid a container can hold when it is full. We measure capacity with two metric units: litres and millilitres.

Millilitres (mL) are used for small amounts, like a glass of juice (about 250 mL) or a small drink bottle. Litres (L) are used for large amounts, like a milk carton (about 1 L) or a bucket (about 10 L). The two units are joined by one fact: \(1\text{ L} = 1000\text{ mL}\).

A measuring jug has a scale printed up the side. To read it, first check how much each mark is worth, then count up from the nearest labelled line to the liquid level.

Measuring jug reading 400 millilitres A measuring jug with a scale marked every 100 millilitres from 0 to 1000. The liquid reaches the fourth mark above 0, so it reads 400 millilitres. 0 500 1000 mL 400 mL
Marks every 100 mL: the liquid is 4 marks above 0, so it reads 400 mL.
Measuring jug with a 250 millilitre scale reading 750 millilitres A measuring jug with a scale marked every 250 millilitres from 0 to 1000. The liquid reaches the 750 millilitre line, which is three quarters of a litre. 0 250 500 750 1000 mL 750 mL
A different jug jumps by 250 mL: always check the marks before you read.

Capacity has no tricky formulas, but these facts help you read jugs and change between the two units.

\[ 1 \text{ L} = 1000 \text{ mL} \]
1 L =1000 mL
\[ 4 \text{ L} = 4000 \text{ mL} \]
4 L =4000 mL
\[ \dfrac{1}{2} \text{ L} = 500 \text{ mL} \]
12 L =500 mL
\[ 250 \text{ mL} = \dfrac{1}{4} \text{ L} \]
250 mL =14 L
Changing units. To go from litres to millilitres, multiply by 1000. To go from millilitres to litres, divide by 1000. So \(5\text{ L} = 5000\text{ mL}\) and \(6000\text{ mL} = 6\text{ L}\).
Benchmarks for estimating. An eye dropper holds about \(1\) mL, a glass about \(250\) mL, a carton of milk about \(1\) L and a bucket about \(10\) L. Compare a container with these to choose a sensible estimate.
Equal amounts. When the same amount is used again and again, multiply. Three lots of \(200\text{ mL}\) is \(3 \times 200 = 600\text{ mL}\).

How to read a measuring jug

  1. Check the marks. Look at two labelled lines and work out how many millilitres apart the small marks are.
  2. Find the line below. Look for the nearest labelled line just under the liquid level.
  3. Count up. Count on in mark-steps from that line to the liquid, then add the amount to read the capacity.

How to solve capacity problems

  1. Same unit. Change litres to millilitres, using \(1\text{ L} = 1000\text{ mL}\).
  2. Choose the operation. Add to find a total, subtract to find how much more is needed, and divide (or count in jumps) to find how many cups or jugs fill a container.
  3. Answer with a unit. Write mL or L, and rename as litres and millilitres if the question asks.
Example 1 — Choosing the unit
Which unit is best for how much water a fish tank holds — litres or millilitres?
Solution

A fish tank holds a large amount of water, so the smaller unit would need huge numbers.

Use the larger unit: litres.

Example 2 — Reading a jug
The jug is marked every 100 mL. How much liquid is in it?
Measuring jug reading 600 millilitres A measuring jug marked every 100 millilitres from 0 to 1000. The liquid reaches one mark above the 500 millilitre line, at 600 millilitres. 0 500 1000 mL ?
Solution
\(\text{each mark}\)\(=\)\(100\text{ mL}\)
\(500 + 100\)\(=\)\(600\text{ mL}\)
500+100=600

The jug holds \(600\text{ mL}\).

Example 3 — Litres and millilitres
Write \(2500\text{ mL}\) in litres and millilitres.
Solution
\(2000\text{ mL}\)\(=\)\(2\text{ L}\)
\(2500 - 2000\)\(=\)\(500\text{ mL}\)
\(2500\text{ mL}\)\(=\)\(2\text{ L } 500\text{ mL}\)
2500 mL =2 L 500 mL

So \(2500\text{ mL} = 2\text{ L } 500\text{ mL}\).

Example 4 — Adding capacity
A jug has \(350\text{ mL}\) of cordial. You pour in \(480\text{ mL}\) of water. How much is in the jug? Is it less than \(1\text{ L}\)?
Solution
\(350 + 480\)\(=\)\(830\text{ mL}\)
\(1\text{ L}\)\(=\)\(1000\text{ mL}\)
\(830\)\(<\)\(1000\)

There is \(830\text{ mL}\), which is less than \(1\text{ L}\).

Example 5 — How much more to 1 L
A bottle holds \(1\text{ L}\) when full. It has \(350\text{ mL}\) of water in it. How much more water is needed to fill it?
Solution
\(1\text{ L}\)\(=\)\(1000\text{ mL}\)
\(1000 - 350\)\(=\)\(650\text{ mL}\)

Another \(650\text{ mL}\) is needed. Check: \(350 + 650 = 1000\).

Example 6 — How many cups?
A jug holds \(5\text{ L}\) of juice. Each cup holds \(500\text{ mL}\). How many cups can be filled?
Solution
\(5\text{ L}\)\(=\)\(5000\text{ mL}\)
\(5000 \div 500\)\(=\)\(10\)

\(10\) cups can be filled. Two \(500\text{ mL}\) cups make \(1\text{ L}\), so \(5\) litres fill \(5 \times 2 = 10\) cups.

Common pitfalls

Check the size of each mark. Watch out for jugs that do not jump by 100 mL. Some go up by 50, 200 or 250 mL, so read two labelled lines before you count.
Use the same unit before comparing. You cannot compare \(1\text{ L}\) with \(850\text{ mL}\) until you write \(1\text{ L}\) as \(1000\text{ mL}\).
A litre is 1000 mL, not 100 mL. Litres and millilitres are very different sizes, so \(1\text{ L} = 1000\text{ mL}\), never \(100\text{ mL}\).
Count the jug-fulls. To fill a \(12\text{ L}\) tub with a \(3\text{ L}\) bucket you need \(12 \div 3 = 4\) buckets, not \(12 - 3 = 9\).

Frequently asked questions

How many millilitres are in a litre?

There are \(1000\) millilitres in \(1\) litre. So \(1\text{ L} = 1000\text{ mL}\), and \(4\text{ L} = 4000\text{ mL}\).

What is capacity?

Capacity is how much liquid a container can hold when it is full. We measure capacity in litres and millilitres.

When do you use litres and when do you use millilitres?

Use litres for large amounts, like a bucket or a fish tank. Use millilitres for small amounts, like a glass of juice or a small drink bottle.

How do you read a measuring jug?

First check how many millilitres are between two labelled lines. Find the nearest labelled line below the liquid, then count up mark by mark to the liquid level.

How do you change litres to millilitres?

Multiply the number of litres by \(1000\). For example, \(7\text{ L} = 7000\text{ mL}\). To change millilitres to litres, divide by \(1000\).

Is 1 litre more than 850 millilitres?

Yes. Change \(1\) litre to the same unit: \(1\text{ L} = 1000\text{ mL}\), and \(1000 > 850\), so \(1\) litre is more than \(850\) millilitres.

How do you work out how many cups a jug fills?

Change the jug to millilitres, then divide by the size of one cup. A \(5\text{ L}\) jug is \(5000\text{ mL}\), and \(5000 \div 500 = 10\) cups.

How do you find the total when the same amount is used several times?

Multiply the amount by the number of times. A recipe that uses \(150\text{ mL}\) of milk, made \(3\) times, uses \(3 \times 150 = 450\text{ mL}\).

More in Volume & Capacity
Compare & order capacity
20 questions