Free printable measurement conversion chart
Grades K–5Length, weight and capacity in both metric and customary units, with the conversion facts children actually need. Print it for the wall, or use the converter below to turn any amount into every other unit in its family.
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Units and conversions
The conversion facts are listed first — those are the ones worth knowing by heart, because everything else can be worked out from them. Below, type an amount and pick its unit and the rest of the family converts.
Switch between metric and customary and the difference becomes obvious. Metric steps by ten, a hundred or a thousand every time, so converting is only ever moving a decimal point. Customary steps by 12, then 3, then 1,760 — numbers with no pattern at all.
That is worth saying to a child rather than leaving them to conclude they are bad at this. Customary conversions genuinely have to be memorized because there is nothing to work out. Metric ones do not, and a child who realizes that stops trying to memorize them.
- 10 mm=1 cm
- 100 cm=1 m
- 1,000 m=1 km
- 12 in=1 ft
- 3 ft=1 yd
- 5,280 ft=1 mi
- 1,000 mg=1 g
- 1,000 g=1 kg
- 16 oz=1 lb
- 2,000 lb=1 ton
- 1,000 mL=1 L
- 8 fl oz=1 cup
- 2 cups=1 pint
- 2 pints=1 quart
- 4 quarts=1 gallon
Pick what you are measuring, type an amount, and choose the unit it is in. Everything else converts.
How to use this measurement chart at home
Measure real things before converting anything. How tall is the door in centimeters? How heavy is a bag of flour? Measuring is a physical skill, and a child who has used a ruler and a set of scales has something for the units to attach to.
Build reference points. A doorway is about two meters. A paperclip is about a gram. A large bottle of drink is about two liters. Children who carry a few of these around can estimate, spot silly answers, and choose sensible units — which is most of what measurement questions test.
Cook something. Measuring jugs, scales and spoons are the customary and metric systems sitting side by side in a kitchen, and halving a recipe is a conversion problem with an obvious reason to get it right.
Why metric is easier, and worth saying so
Every metric step is ten, a hundred or a thousand. Converting meters to centimeters means multiplying by a hundred, which means moving the decimal point two places. The whole system is built on the same place value children already know.
The prefixes carry the information too. Milli means a thousandth, centi means a hundredth, kilo means a thousand. Learn those three and millimeter, centimeter and kilometer stop being separate words to memorize.
The customary system has none of that. Twelve inches in a foot, three feet in a yard, sixteen ounces in a pound, eight fluid ounces in a cup. There is no pattern because these units arrived from different places over centuries, and a child struggling with them is not struggling with math.
Choosing the right unit
A question that asks how tall a tree is expects meters, not millimeters. Both are correct, but one produces a number a person can picture and the other produces 9,000 of something.
The rule of thumb is to pick the unit that gives a number roughly between one and a thousand. That is why we measure people in centimeters or feet, roads in kilometers or miles, and medicine in milliliters.
This gets tested more than it gets taught. Multiple choice questions frequently offer the right number with the wrong unit, and a child with reference points in their head spots it instantly.
Where measurement usually goes wrong
Multiplying when you should divide. Going from a big unit to a small one means more of them, so the number gets bigger. Checking whether the answer should be larger or smaller before calculating catches most of these.
Starting a ruler at the end rather than at zero. Many rulers have a small margin before the zero mark, and measuring from the edge gives an answer a few millimeters out every time.
Mixing systems in one calculation. Adding inches to centimeters. They have to be converted to a common unit first.
Dropping the unit from the answer. A number on its own does not answer a measurement question — 5 could be centimeters, meters or miles.
After the chart goes up
A chart explains the idea but gives a child nothing to do. These do the rest.
- measurement at Mathify Kids — every topic in this area, sorted by grade.
- customary units worksheets — printable practice.
- metric units worksheets — the next step once this is solid.
- telling time worksheets — more practice in the same area.
Everything at this level: Kindergarten math · Grade 1 math · Grade 2 math · Grade 3 math · Grade 4 math · Grade 5 math
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Questions parents ask
What are the metric units of length?
Millimeters, centimeters, meters and kilometers. Ten millimeters make a centimeter, a hundred centimeters make a meter, and a thousand meters make a kilometer. Every step is a power of ten, which is the whole point of the system.
What are the customary units of length?
Inches, feet, yards and miles. Twelve inches make a foot, three feet make a yard, and 1,760 yards make a mile. None of those numbers relate to each other, which is why they have to be learned rather than worked out.
What is the difference between mass and weight?
Mass is how much matter something contains; weight is how hard gravity pulls on it. On Earth they track each other closely, so grams and pounds get used loosely for both. Strictly, metric measures mass and the customary system measures weight — a distinction that starts mattering in science around Grade 6.
How many cups are in a gallon?
Sixteen. Two cups make a pint, two pints make a quart, and four quarts make a gallon, so 2 × 2 × 4 = 16. The doubling pattern in the first steps is the easiest part of the customary system to remember.
Which unit should my child use?
Whichever gives a sensible number. A pencil measured in kilometers or a road measured in millimeters both produce answers nobody can picture. Choosing the right unit is a real skill and is often what a question is actually testing.
What grade is this measurement chart for?
Kindergarten through Grade 5. Comparing lengths without units comes first, then measuring with rulers around Grade 1 or 2, standard units in Grade 2 or 3, and converting between units by Grades 4 and 5.
Is this measurement chart free to print?
Yes. Open it full size and print as many copies as you need for home or a classroom, with no account and no watermark. Reselling it or re-hosting the file elsewhere is not allowed — link to this page instead.