Converting Millilitres and Litres (KS2)

ME6Converting Capacity

Millilitres ↔ litres with ×1000 and ÷1000.

Capacity converts exactly like mass — three places, one fact.

1.5 l = ? ml

l → ml: × 1000

1.5 × 1000 = 1500 ml

l → ml: × 1000 · ml → l: ÷ 1000

Learn the 3-Step Method

1The conversion number is 1000.

1000 ml = 1 l — three places to slide.

1000

2l → ml: multiply.

1.5 l = 1500 ml.

1.5 → 1500

3ml → l: divide.

250 ml = 0.25 l.

250 → 0.25

💡 Key IdeaLength, mass, capacity — one skill, three costumes: multiply or divide by 10, 100 or 1000 by sliding digits.

Worked Example

A jug holds 2 l. Sam pours out three 250 ml glasses. How much juice is left?

Same units

2 l = 2000 ml

→

Poured out

3 × 250 = 750 ml

→

Left

2000 − 750 = 1250 ml

→

✓ Answer

1250 ml = 1.25 l

Watch Out! Common Mistakes

Two places instead of three.

1.5 l = 150 ml ✕

Wrong! ×1000 slides three places: 1500 ml.

Mixing units in one sum.

2 l − 750 ml = 1.25 ml ✕ (units!)

Careful! The method needs same units — 2000 ml − 750 ml = 1250 ml = 1.25 l. State the unit correctly.

Forgetting how many glasses.

2000 − 250 = 1750 ml ✕

Read again! THREE glasses were poured: 3 × 250 = 750. Left: 1250 ml.

⬇ Cheat Sheet

CONVERTING CAPACITY

1000 ml = 1 l.
l → ml: × 1000. ml → l: ÷ 1000.
Same units before calculating.
Multi-step: total poured first, then subtract.

Example: 2 l − (3 × 250 ml) = 2000 − 750 = 1250 ml = 1.25 l

📖 Continue Your Journey

✓ ME1 Units of Length ✓ ME2 Converting Length ✓ ME3 Units of Mass ✓ ME4 Converting Mass ✓ ME5 Units of Capacity ME6 Converting Capacity ME7 Reading Scales ME8 Perimeter ME9 Area of Rectangles ME10 Area of Triangles ME11 Area of Parallelograms ME12 Compound Shapes ME13 Volume of Cuboids ME14 Telling the Time ME15 Time Calculations ME16 Money Calculations ME17 Imperial and Metric Units ME18 Measurement Problem Solving

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Next Lesson: ME7 Reading ScalesWork out what each mark is worth.

📄 Free printable: Download the Converting Capacity cheat sheet (PDF) — keep it by your child's desk.

Quick summary

1000 ml = 1 l; multiply to go to ml, divide to go to litres.
Slide three places: 1.5 l = 1500 ml, 250 ml = 0.25 l.
Convert to the same unit before adding or subtracting.
Multi-step problems: work out the total poured before subtracting.

Frequently asked questions

How do you convert litres to millilitres?

Multiply by 1000: 1.5 l = 1500 ml. To go back, divide: 250 ml = 0.25 l.

How do you solve jug-and-glasses problems?

Convert everything to millilitres, find the total poured out, then subtract from the jug's capacity: 2000 − (3 × 250) = 1250 ml left.

Why do all metric conversions feel the same?

Because they are — length, mass and capacity all use powers of ten, so one digit-sliding skill covers the lot.

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ME5 Units of Capacity