Skip to content
BooknBoost

Free printable

Metric Conversion Chart: Length, Weight, Volume and Temperature

= means the factor is exact. ≈ means it’s rounded to the nearest thousandth. Every number is worked out from the official definitions, not copied from another chart.

Download the PDF(1 page)
Metric prefixes: each step is 10 times the next
PrefixTimes the base unitExample
kilo (k)1,0001 kilometer (km) = 1,000 m
hecto (h)1001 hectometer (hm) = 100 m
deka (da)101 dekameter (dam) = 10 m
base unit1meter (m), gram (g), liter (L)
deci (d)0.1 (1/10)1 decimeter (dm) = 0.1 m
centi (c)0.01 (1/100)1 centimeter (cm) = 0.01 m
milli (m)0.001 (1/1,000)1 millimeter (mm) = 0.001 m

Going to a smaller unit, multiply. Going to a bigger unit, divide. The order: King Henry Died By Drinking Chocolate Milk.

Length

Length: Metric
1 centimeter (cm)=10 mm
1 meter (m)=100 cm
1 meter (m)=1,000 mm
1 kilometer (km)=1,000 m
Length: US customary
1 foot (ft)=12 in
1 yard (yd)=3 ft
1 yard (yd)=36 in
1 mile (mi)=5,280 ft
1 mile (mi)=1,760 yd
Length: US and metric
1 inch (in)=2.54 cm
1 cmis about0.394 in
1 inch (in)=25.4 mm
1 millimeter (mm)is about0.039 in
1 foot=0.3048 m
1 mis about3.281 ft
1 yard=0.9144 m
1 mis about1.094 yd
1 mile=1.609344 km
1 kmis about0.621 mi

Weight (mass)

Weight (mass): Metric
1 gram (g)=1,000 mg
1 kilogram (kg)=1,000 g
1 metric ton (t)=1,000 kg
Weight (mass): US customary
1 pound (lb)=16 oz
1 ton=2,000 lb
Weight (mass): US and metric
1 ounce (oz)is about28.35 g
1 gis about0.035 oz
1 poundis about0.454 kg
1 kgis about2.205 lb
1 ton=907.18474 kg
1 metric tonis about1.102 tons

Volume (capacity)

Volume (capacity): Metric
1 liter (L)=1,000 mL
1 milliliter (mL)=1 cm³
1 cubic meter (m³)=1,000 L
Volume (capacity): US customary
1 tablespoon (tbsp)=3 tsp
1 fluid ounce (fl oz)=2 tbsp
1 cup=8 fl oz
1 pint (pt)=2 cups
1 quart (qt)=2 pt
1 gallon (gal)=4 qt
Volume (capacity): US and metric
1 teaspoon (tsp)is about4.929 mL
1 mLis about0.203 tsp
1 fl ozis about29.574 mL
1 Lis about33.814 fl oz
1 cupis about236.588 mL
1 Lis about4.227 cups
1 pintis about0.473 L
1 Lis about2.113 pt
1 quartis about0.946 L
1 Lis about1.057 qt
1 gallonis about3.785 L
1 Lis about0.264 gal

Temperature

°F = °C × 9/5 + 32 (× 9/5 is the same as × 1.8)

°C = (°F − 32) × 5/9

K = °C + 273.15 (kelvin, used in science)

Celsius to Fahrenheit
°C°FNote
−40−40the two scales meet
−20−4
−1014
032water freezes
1050
2068room temperature
2577
3086
3798.6body temperature
40104
100212water boils (at sea level)

The exact definitions

  • 1 inch = 2.54 centimeters
  • 1 pound = 0.45359237 kilogram
  • 1 gallon = 231 cubic inches = 3.785411784 liters

Every US-to-metric factor on this chart is worked out from these three, as listed in NIST Handbook 44. A rounded factor is rounded only at the last step.

Here’s a fact most charts skip: just three definitions connect US lengths, weights and volumes to metric ones. They’re 1 inch = 2.54 cm, 1 pound = 0.45359237 kg and 1 gallon = 231 cubic inches. Every factor on this chart comes from those three, and it marks which numbers are exact.

Coach Crissy

Math instructor

Published
October 20, 2026
Reading time
4 min read

How to use the chart: two quick examples

Find the unit you have on the left, then multiply by the number next to it. Between US and metric units, every factor is there both ways, so you can always multiply.

Inches to centimeters
Exact

A shelf is 30 inches wide. How wide is it in centimeters?

The working

  1. Find 1 inch in the Length table: 1 inch = 2.54 cm, and that factor is exact.
  2. Multiply: 30 × 2.54 = 76.2.

Answer: 76.2 cm

Fahrenheit to Celsius
Temperature

The weather report says 68°F. What is that in Celsius?

The working

  1. Use °C = (°F − 32) × 5/9.
  2. Subtract first: 68 − 32 = 36.
  3. Then multiply: 36 × 5/9 = 20. It’s in the temperature table too.

Answer: 20°C

3 mistakes that cost points

Mistake 1: multiplying when you should divide

Check the size of your answer. A centimeter is smaller than an inch, so any length has more centimeters than inches: 10 inches is 25.4 cm. If your number got smaller, you went the wrong way.

Mistake 2: rounding 2.54 to 2.5

It looks harmless, but for 100 inches, 2.5 gives 250 cm when the right answer is 254 cm. Use the full factor and round once, at the end.

Mistake 3: mixing up ounces and fluid ounces

An ounce (oz) measures weight. A fluid ounce (fl oz) measures volume. A cup of water is 8 fl oz and weighs a little more than 8 oz, so the two are close, yet they measure different things.

The exact definitions come from NIST Handbook 44, Appendix C, and the base units from NIST’s list of SI units.

Frequently asked questions

How do you convert metric measurements?

Inside the metric system, every step is a power of 10, so you multiply or divide by 10, 100 or 1,000. Going to a smaller unit, multiply: 2.5 meters is 250 centimeters. Going to a bigger unit, divide: 750 grams is 0.75 kilogram. Between metric and US units, multiply by the factor in the chart.

What are the 7 metric units?

The seven SI base units are the meter (length), kilogram (mass), second (time), ampere (electric current), kelvin (temperature), mole (amount of a substance) and candela (brightness of light). In everyday math you mostly use the meter, the gram and the liter, plus the prefixes from kilo to milli.

What is 1 inch in metric?

One inch is exactly 2.54 centimeters, or 25.4 millimeters. It has been defined that way since 1959, so it isn't a rounded number. Going the other way, 1 centimeter is about 0.394 inch, so a 30-centimeter ruler is a little under a foot long, about 11.8 inches.

What is a metric conversion chart?

It's a table of the numbers you multiply by to change one unit into another, like inches to centimeters or liters to quarts. A good one shows the metric prefixes, the units inside each system and the factors between them, and tells you which numbers are exact and which are rounded.

Keep going

Written by

Coach Crissy

Math instructor

Coach Crissy teaches the video lessons behind the BooknBoost GED math course, working through GED-style problems on camera: ratios and proportions, percent and interest, mean, median and mode, slope, and the geometry students meet on test day.

Metric Conversion Chart

Metric prefixes, length, weight, volume and temperature, inside each system and between US and metric units.

BooknBoost
kilo(k)× 1,000
hecto(h)× 100
deka(da)× 10
base unitm, g, L× 1
deci(d)× 0.1
centi(c)× 0.01
milli(m)× 0.001
Each step is 10 times the next. To a smaller unit (right), multiply. To a bigger unit (left), divide.In order: King Henry Died By Drinking Chocolate Milk

Length

Metric

1 centimeter (cm)=10 mm
1 meter (m)=100 cm
1 meter (m)=1,000 mm
1 kilometer (km)=1,000 m

US customary

1 foot (ft)=12 in
1 yard (yd)=3 ft
1 yard (yd)=36 in
1 mile (mi)=5,280 ft
1 mile (mi)=1,760 yd

US and metric

1 inch (in)=2.54 cm
1 cm≈0.394 in
1 inch (in)=25.4 mm
1 millimeter (mm)≈0.039 in
1 foot=0.3048 m
1 m≈3.281 ft
1 yard=0.9144 m
1 m≈1.094 yd
1 mile=1.609344 km
1 km≈0.621 mi

Weight (mass)

Metric

1 gram (g)=1,000 mg
1 kilogram (kg)=1,000 g
1 metric ton (t)=1,000 kg

US customary

1 pound (lb)=16 oz
1 ton=2,000 lb

US and metric

1 ounce (oz)≈28.35 g
1 g≈0.035 oz
1 pound≈0.454 kg
1 kg≈2.205 lb
1 ton=907.18474 kg
1 metric ton≈1.102 tons

Volume (capacity)

Metric

1 liter (L)=1,000 mL
1 milliliter (mL)=1 cm³
1 cubic meter (m³)=1,000 L

US customary

1 tablespoon (tbsp)=3 tsp
1 fluid ounce (fl oz)=2 tbsp
1 cup=8 fl oz
1 pint (pt)=2 cups
1 quart (qt)=2 pt
1 gallon (gal)=4 qt

US and metric

1 teaspoon (tsp)≈4.929 mL
1 mL≈0.203 tsp
1 fl oz≈29.574 mL
1 L≈33.814 fl oz
1 cup≈236.588 mL
1 L≈4.227 cups
1 pint≈0.473 L
1 L≈2.113 pt
1 quart≈0.946 L
1 L≈1.057 qt
1 gallon≈3.785 L
1 L≈0.264 gal

Temperature

°F = °C × 9/5 + 32 (× 9/5 is the same as × 1.8)

°C = (°F − 32) × 5/9

K = °C + 273.15 (kelvin, used in science)

°C−40−20−100102025303740100
°F−40−414325068778698.6104212

−40 °C: the two scales meet · 0 °C: water freezes · 20 °C: room temperature · 37 °C: body temperature · 100 °C: water boils (at sea level)

The exact definitions

1 inch = 2.54 centimeters

1 pound = 0.45359237 kilogram

1 gallon = 231 cubic inches = 3.785411784 liters

Every US-to-metric number on this chart is worked out from these three (NIST Handbook 44). = marks an exact factor. ≈ marks one rounded to the nearest thousandth.

booknboost.com · Free GED math practice= exact · ≈ rounded to the nearest thousandth