Metric Conversion Chart, Worksheets & Quiz

Print the chart, the staircase poster, and a worksheet and quiz for each grade band, or work through the converter and practice quiz further down this page. Every printable comes in US Letter and A4, and every worksheet and quiz has an answer key that shows the working.

Printable metric conversion worksheets and quizzes with answer keys

Each metric unit conversion worksheet is paired with a quiz at the same level. Use the switches at the top of the page to change the paper size, show the answer key links, or print the chart in ink-saver black and white.

• Grades 4-5 (ages 9 to 11): moving the decimal point on the staircase with whole numbers, comparing units and simple word problems. The US Letter set adds feet, yards, ounces and quarts.
• Grades 6-8 (ages 11 to 14): decimals, mixed units, area and volume, temperature, and US-to-metric conversion on the Letter set.
• High school (ages 14 to 18): all 24 prefixes, scientific notation, rates and density, and multi-step dimensional analysis.

The fill-in chart works as a quick check before a unit test: students rebuild the prefix table from memory and mark it against the key.

Metric conversion chart: all 24 SI prefixes

The metric system is built on powers of ten. A prefix names the power and attaches to a base unit: the meter for length, the gram for mass, the liter for volume. Kilo means 1,000, so a kilometer is 1,000 meters. Milli means one thousandth, so a milliliter is 0.001 liter. The chart below is a metric system chart you can print or read on screen.

This metric prefixes chart shades the six prefixes taught in most classrooms (kilo, hecto, deka, deci, centi and milli) and the five that matter next in science: tera, giga, mega, micro and nano.

Four of the prefixes are new. In November 2022 the General Conference on Weights and Measures added quetta (10³⁰), ronna (10²⁷), ronto (10⁻²⁷) and quecto (10⁻³⁰) because data science was outgrowing yotta. A chart that stops at yotta and yocto is missing them.

The metric staircase: King Henry Died By Drinking Chocolate Milk

The staircase, also called the metric ladder, lists the seven units used most often in order of size. The sentence gives the order: King Henry Died By Drinking Chocolate Milk stands for kilo, hecto, deka, base unit, deci, centi, milli.

How to use the staircase

1. Write the number and find both units on the staircase.
2. Count the steps from the starting unit to the unit you want.
3. Moving down toward milli multiplies by 10 for each step, so move the decimal point right. Moving up toward kilo divides by 10 for each step, so move it left.

Most metric conversions are nothing more than this decimal move. Add zeros when the number runs out of digits.

Worked examples

3.5 km to meters: kilo to the base unit is 3 steps down, so the decimal point moves 3 places right. 3.5 km = 3,500 m. 450 mg to grams: milli to the base unit is 3 steps up, so the decimal point moves 3 places left. 450 mg = 0.45 g.

Metric conversion table: US customary to metric

Every US customary unit is defined in metric terms, so each factor in this unit conversion chart is exact. Multiply to go from US to metric and divide to come back. The metric-only tab is a metric system conversion chart for conversions inside the system, such as kilometers to meters or liters to milliliters.

Check the size of your answer before you trust it: inches become more centimeters (about 2.5 times as many) and pounds become fewer kilograms (about 0.45 times as many).

Kitchen, liquid, weight and temperature conversions

Recipes mix systems more than any other place. The kitchen conversion chart in the download section covers the common cases. These are the numbers to remember.

• Liquid: 1 cup = 236.6 mL (recipes round to 240 mL), 1 tablespoon = 14.8 mL (15 mL), 1 teaspoon = 4.9 mL (5 mL), 1 liter = 1.057 quarts.
• Weight: 1 ounce = 28.35 g and 1 pound = 453.6 g.
• Cups to grams: there is no single factor because a cup measures volume. A cup of all-purpose flour is about 120 g and a cup of granulated sugar is about 198 g.
• Temperature: 350 °F = 177 °C, which recipes round to 180 °C.

Metric unit converter

Choose a quantity, type a value and read the result with the steps. Conversions inside the metric system show the staircase and the decimal move. Conversions between systems show the fractions that cancel the units.

Metric conversion practice

The practice quiz makes a new problem each time from the same sets as the worksheets, so the rounding rule matches the printed sheets. Equivalent answers count: 3,500 and 3500 are the same, and so are 3.2e5 and 3.2 × 10^5.

How teachers can use the set

• Teach: hang the staircase poster and walk through the worked examples on the board.
• Practice: assign the worksheet for the grade band. The answer key gives each answer with one line of working, so students can check themselves.
• Check: give the matching quiz, which has 12 multiple choice and 3 short answer questions, or use the fill-in chart as an exit ticket.
• Differentiate: hand fast finishers the next band up. The layout is the same on Letter and A4.
• Save ink: switch the chart to its black and white version.

For the systems behind these units, read units of measurement and examples of SI units. In chemistry the same conversions run through the molar mass calculator, which turns grams into moles. More free sheets are in the printables hub.

Frequently asked questions

How do you convert units in the metric system?

Count the steps between the two units on the metric staircase, then move the decimal point that many places. Each step down to a smaller unit multiplies by 10, so the decimal moves right. Each step up to a bigger unit divides by 10, so it moves left. Example: 3.5 km to m is 3 steps down, so 3.5 becomes 3,500 m.

What is the easiest way to remember the metric prefixes?

Use "King Henry Died By Drinking Chocolate Milk". The first letters give kilo, hecto, deka, base unit, deci, centi and milli, from the largest unit to the smallest. Each step to the right is a factor of 10.

How many SI prefixes are there?

There are 24, from quetta (10³⁰) to quecto (10^-30). Four of them are new: quetta (Q), ronna (R), ronto (r) and quecto (q) were adopted in November 2022, the first additions since 1991. Most classrooms only use kilo, hecto, deka, deci, centi and milli, plus mega, giga, micro and nano in science.

How do I convert US customary units to metric?

Multiply by the exact factor: 1 in = 2.54 cm, 1 ft = 0.3048 m, 1 mi = 1.609344 km, 1 lb = 0.45359237 kg, 1 gal = 3.785411784 L. To go back, divide by the same factor. Keep the full factor during the work and round only the final answer.

How do I convert Celsius to Fahrenheit?

Multiply the Celsius value by 9/5 and add 32: °F = °C × 9/5 + 32. To go the other way, subtract 32 and multiply by 5/9. Kelvin is °C + 273.15. For a quick estimate, double the Celsius value and add 30: 20 °C is about 70 °F (exactly 68).

How many milliliters are in a liter?

There are 1,000 mL in 1 L. A milliliter is also exactly 1 cm³, and a liter is exactly 1 dm³ (a cube 10 cm on each side), which is why 1 L = 1,000 cm³.

Are the printable metric conversion worksheets free?

Yes. Print them for classroom or home use. If you share them online, link to this page instead of re-hosting the PDFs.

What is the difference between the US Letter and A4 versions?

The layout is the same and the paper size differs. The US Letter set (8.5 × 11 in) covers US customary and metric units. The A4 set (210 × 297 mm) is metric only, so its worksheets stay inside the metric system, including area, volume and kelvin. The A4 kitchen chart is the exception: it converts American recipes.

Do the worksheets and quizzes have answer keys?

Yes. Each worksheet, quiz and the fill-in chart has a separate answer key PDF. Every answer comes with a one-line working. Switch on "Include answer keys" in the download section to show the key links.

Is the converter exact?

Yes. It uses exact fractions, not floating-point numbers, and every factor is a definition (for example 1 in = 2.54 cm exactly). A result is rounded only for display, and a rounded result is marked with the approximately-equal sign.