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Measurement · Lesson 6 of 16

Capacity: Millilitres and Litres

Capacity is how much a container holds. There are 1000 millilitres in 1 litre, so convert by multiplying or dividing by 1000.

What you will learn

  • Say what millilitres and litres measure.
  • Read a measuring jug.
  • Convert between millilitres and litres.
  • Solve simple problems about liquids.

Before you start: you should know that containers hold different amounts and be able to multiply by 10001000. See Comparing Length, Mass and Capacity.

The idea

Capacity is how much a container can hold, and for liquids we measure it in millilitres (ml) and litres (l). Milli means a thousandth, so 10001000 ml make 11 litre.

Containers: 1 litre, 500 ml, 250 ml1 litre (jug container) is full; 500 ml (jug container) is half full; 250 ml (jug container) is a quarter full.1 litrefull500 mlhalf full250 mla quarter full
A 1 litre jug full, half full and a quarter full. Half a litre is 500 ml and a quarter of a litre is 250 ml.

Choosing a unit

Use millilitres for small amounts (a teaspoon, a cup, a can) and litres for bigger ones (a bottle of juice, a bucket, a fish tank).

Bar comparison of Teaspoon, Cup, Bottle and JugTeaspoon is 5 ml; Cup is 250 ml; Bottle is 500 ml; Jug is 1500 ml. Longer bars are bigger amounts.Teaspoon5 mlCup250 mlBottle500 mlJug1500 ml
Capacities of everyday containers in millilitres.

Reading a jug

Look at the level and find the nearest mark. Work out what each small mark is worth first. If the gap from 00 to 500500 ml has 55 spaces, each mark is 100100 ml.

Sorted into groups: Fraction of a litre, MillilitresFraction of a litre: 1/4, 1/2, 3/4, 1. Millilitres: 250 ml, 500 ml, 750 ml, 1000 ml.Fraction of a litre1/41/23/41Millilitres250 ml500 ml750 ml1000 ml
Quarter, half, three-quarter and whole litres in millilitres.

Converting

Litres to millilitres: multiply by 10001000. Millilitres to litres: divide by 10001000.

Worked examples

Example 1: Convert

Change 2.52.5 litres to millilitres.

  1. 2.5×1000=25002.5 \times 1000 = 2500.

Answer: 25002500 ml

Example 2: Pouring out

A 1.51.5 litre bottle has 400400 ml poured out. How much is left?

  1. 1.51.5 litres is 15001500 ml.
  2. 1500−400=11001500 - 400 = 1100.

Answer: 11001100 ml, or 1.11.1 litres.

Example 3: Filling cups

How many 250250 ml cups can be filled from a 22 litre bottle?

  1. 22 litres is 20002000 ml.
  2. 2000÷250=82000 \div 250 = 8.

Answer: 88 cups

Tip: a litre of water has a mass of 11 kg, a handy link between capacity and mass.

Why it matters

Cooking, drinks, fuel, medicine and aquariums all use capacity. Being able to convert quickly helps you compare the sizes of bottles and follow a recipe in either unit.

Practice

Your turn. Type or choose an answer, then press Check. Getting one wrong is fine, that is what practice is for. You can try as many times as you like.

Question 1 of 8

How many millilitres are in 33 litres?

Question 2 of 8

Change 25002500 ml to litres.

Question 3 of 8

Four cups each hold 250250 ml. How many millilitres do they hold altogether?

Question 4 of 8

A jug holds 1.51.5 litres. 400400 ml is poured out. How many millilitres are left?

Question 5 of 8

Which unit is best for the amount of medicine in a spoon?

Choose one answer

Question 6 of 8

Five glasses each hold 200200 ml. What is the total in litres?

Question 7 of 8

How many 250250 ml cups can be filled from 22 litres?

Question 8 of 8

A jug is 34\frac{3}{4} full and holds 11 litre when full. How much is in it?

Choose one answer