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Unit Conversion Chart: Length, Weight, Volume & More

Complete unit conversion chart for length, weight, volume, temperature, and area. Common conversion factors with formulas and real-world examples.

Alamzeb Khan
Alamzeb Khan
Updated 9 min read

TL;DR

A unit conversion chart is a reference table that shows the mathematical relationship between different units of measurement — like inches to centimeters, pounds to kilograms, or gallons to liters. This guide covers the most commonly needed conversions for length, weight, volume, area, temperature, and speed, with exact conversion factors, formulas, and practical examples you can use immediately.


What Is a Unit Conversion Chart?

A unit conversion chart is a reference tool that lists the exact ratios between different units of measurement so you can quickly translate a value from one system to another. It is an essential resource for cooking, construction, travel, shipping, science, and everyday tasks where measurements need to cross system boundaries.

The two primary measurement systems in use today are the metric system (meters, grams, liters) used by most of the world, and the imperial/US customary system (feet, pounds, gallons) used primarily in the United States. Knowing how to convert between them is a practical skill that comes up constantly — whether you are following a recipe from a British cookbook, buying lumber, or checking your luggage weight before a flight.

Every conversion in this guide uses exact or officially recognized factors. Where rounding is applied, it is noted.


Length Conversion Chart

Length is the most commonly converted measurement category. Here are the conversions you will use most often:

Imperial to Metric

FromToMultiply byExample
InchesCentimeters2.5412 in × 2.54 = 30.48 cm
FeetMeters0.30486 ft × 0.3048 = 1.8288 m
YardsMeters0.9144100 yd × 0.9144 = 91.44 m
MilesKilometers1.6093426.2 mi × 1.60934 = 42.16 km

Metric to Imperial

FromToMultiply byExample
CentimetersInches0.3937180 cm × 0.3937 = 70.87 in
MetersFeet3.28081.83 m × 3.2808 = 6.004 ft
MetersYards1.0936100 m × 1.0936 = 109.36 yd
KilometersMiles0.621410 km × 0.6214 = 6.214 mi

Within Imperial

FromToFactor
1 foot12 inches
1 yard3 feet
1 mile5,280 feet
1 mile1,760 yards

Within Metric

FromToFactor
1 centimeter10 millimeters
1 meter100 centimeters
1 kilometer1,000 meters

Practical examples:

  • You are 5 feet 10 inches tall. In centimeters: (5 × 12 + 10) × 2.54 = 70 × 2.54 = 177.8 cm.
  • A 5K race is 5 kilometers. In miles: 5 × 0.6214 = 3.107 miles.
  • Your room is 4.5 meters wide. In feet: 4.5 × 3.2808 = 14.76 feet.

Weight (Mass) Conversion Chart

Weight conversions come up constantly in cooking, shipping, fitness, and travel.

Imperial to Metric

FromToMultiply byExample
Ounces (oz)Grams (g)28.34958 oz × 28.3495 = 226.8 g
Pounds (lb)Kilograms (kg)0.4536150 lb × 0.4536 = 68.04 kg
Pounds (lb)Grams (g)453.5920.5 lb × 453.592 = 226.8 g
Tons (US short)Metric tons0.90722 tons × 0.9072 = 1.814 metric tons

Metric to Imperial

FromToMultiply byExample
Grams (g)Ounces (oz)0.03527500 g × 0.03527 = 17.64 oz
Kilograms (kg)Pounds (lb)2.204675 kg × 2.2046 = 165.35 lb
Metric tonsTons (US short)1.10231 metric ton × 1.1023 = 1.1023 tons

Within Imperial

FromToFactor
1 pound16 ounces
1 ton (US short)2,000 pounds

Within Metric

FromToFactor
1 gram1,000 milligrams
1 kilogram1,000 grams
1 metric ton1,000 kilograms

Practical examples:

  • Your checked luggage limit is 23 kg. In pounds: 23 × 2.2046 = 50.7 lbs.
  • A recipe calls for 200 grams of flour. In cups: 200 g is approximately 1.6 cups (flour is about 125 g per cup, though this varies by type).
  • You weigh 180 pounds. In kilograms: 180 × 0.4536 = 81.6 kg.

Volume Conversion Chart

Volume conversions are critical in cooking, where recipes from different countries use different systems.

Imperial/US to Metric

FromToMultiply byExample
Teaspoons (tsp)Milliliters (mL)4.9292 tsp × 4.929 = 9.86 mL
Tablespoons (tbsp)Milliliters (mL)14.7873 tbsp × 14.787 = 44.36 mL
Fluid ounces (fl oz)Milliliters (mL)29.57358 fl oz × 29.5735 = 236.6 mL
Cups (US)Milliliters (mL)236.5882 cups × 236.588 = 473.2 mL
Cups (US)Liters (L)0.23664 cups × 0.2366 = 0.946 L
Pints (US)Liters (L)0.47321 pint × 0.4732 = 0.473 L
Quarts (US)Liters (L)0.94641 quart × 0.9464 = 0.946 L
Gallons (US)Liters (L)3.78545 gal × 3.7854 = 18.93 L

Metric to Imperial/US

FromToMultiply byExample
Milliliters (mL)Fluid ounces (fl oz)0.03381750 mL × 0.03381 = 25.36 fl oz
Liters (L)Cups (US)4.22681 L × 4.2268 = 4.23 cups
Liters (L)Quarts (US)1.05672 L × 1.0567 = 2.11 quarts
Liters (L)Gallons (US)0.264220 L × 0.2642 = 5.28 gallons

Common Kitchen Equivalents

MeasureEquivalent
1 tablespoon3 teaspoons
1 fluid ounce2 tablespoons
1 cup8 fluid ounces
1 cup16 tablespoons
1 pint2 cups
1 quart4 cups
1 gallon4 quarts
1 gallon128 fluid ounces

Practical examples:

  • A wine bottle is 750 mL. In fluid ounces: 750 × 0.03381 = 25.36 fl oz (about 5 standard pours of 5 oz each).
  • A recipe calls for 500 mL of broth. In cups: 500 ÷ 236.588 = 2.11 cups (just over 2 cups).
  • Your car’s engine takes 5 quarts of oil. In liters: 5 × 0.9464 = 4.73 liters.

Area Conversion Chart

Area conversions are essential for real estate, construction, gardening, and land measurement.

FromToMultiply byExample
Square inches (in²)Square centimeters (cm²)6.4516144 in² × 6.4516 = 929.03 cm²
Square feet (ft²)Square meters (m²)0.09291,500 ft² × 0.0929 = 139.35 m²
Square meters (m²)Square feet (ft²)10.7639100 m² × 10.7639 = 1,076.39 ft²
AcresSquare feet (ft²)43,5600.5 acre × 43,560 = 21,780 ft²
AcresHectares0.404710 acres × 0.4047 = 4.047 hectares
HectaresAcres2.47115 hectares × 2.4711 = 12.36 acres
Square milesSquare kilometers2.591 mi² × 2.59 = 2.59 km²
Square kilometersSquare miles0.386110 km² × 0.3861 = 3.86 mi²

Practical examples:

  • Your apartment is 850 square feet. In square meters: 850 × 0.0929 = 78.97 m².
  • A soccer field is about 7,000 m². In square feet: 7,000 × 10.7639 = 75,347 ft² (about 1.73 acres).
  • You are buying a 0.25-acre lot. In square feet: 0.25 × 43,560 = 10,890 ft².

For detailed square footage calculations, see our guide on how to calculate square footage.


Temperature Conversion Chart

Temperature is the one conversion that uses a formula rather than a simple multiplication factor.

Formulas

ConversionFormulaExample
Fahrenheit to Celsius°C = (°F - 32) × 5/972°F → (72 - 32) × 5/9 = 22.2°C
Celsius to Fahrenheit°F = (°C × 9/5) + 32100°C → (100 × 9/5) + 32 = 212°F
Celsius to KelvinK = °C + 273.1525°C → 25 + 273.15 = 298.15 K
Fahrenheit to KelvinK = (°F - 32) × 5/9 + 273.1568°F → (68 - 32) × 5/9 + 273.15 = 293.15 K

Common Reference Points

DescriptionFahrenheitCelsius
Water freezes32°F0°C
Room temperature68-72°F20-22°C
Body temperature98.6°F37°C
Water boils212°F100°C
Oven at “moderate”350°F177°C
Oven at “hot”425°F218°C

Quick mental math trick: To roughly convert Celsius to Fahrenheit, double the Celsius value and add 30. Example: 20°C → (20 × 2) + 30 = 70°F (actual answer: 68°F). Close enough for everyday use.


Speed Conversion Chart

Speed conversions come up in driving, running, cycling, and wind speed.

FromToMultiply byExample
Miles per hour (mph)Kilometers per hour (km/h)1.6093465 mph × 1.60934 = 104.6 km/h
Kilometers per hour (km/h)Miles per hour (mph)0.6214100 km/h × 0.6214 = 62.14 mph
Miles per hour (mph)Meters per second (m/s)0.4470460 mph × 0.44704 = 26.82 m/s
KnotsMiles per hour (mph)1.1507830 knots × 1.15078 = 34.52 mph
KnotsKilometers per hour (km/h)1.85230 knots × 1.852 = 55.56 km/h

Practical examples:

  • A speed limit sign in Canada reads 110 km/h. In mph: 110 × 0.6214 = 68.4 mph.
  • You ran a 10K in 50 minutes. Your pace was 12 km/h (10 ÷ 0.833 hours). In mph: 12 × 0.6214 = 7.46 mph.
  • A tropical storm has winds of 60 knots. In mph: 60 × 1.15078 = 69 mph.

Data Storage Conversion Chart

With digital storage, conversions use factors of 1,000 (SI/marketing) or 1,024 (binary/actual). Here are the SI/marketing values used by drive manufacturers:

FromToFactor
1 Kilobyte (KB)1,000 Bytes
1 Megabyte (MB)1,000 KB1,000,000 Bytes
1 Gigabyte (GB)1,000 MB1,000,000,000 Bytes
1 Terabyte (TB)1,000 GB1,000,000,000,000 Bytes

Operating systems often use binary (1,024 base), which is why a 500 GB drive shows as about 465 GB in your file manager. The “missing” space is not lost — it is a difference in how the number is calculated.

Practical example:

  • Your phone has 128 GB of storage. In MB: 128 × 1,000 = 128,000 MB. A typical photo is about 5 MB, so you can store roughly 25,600 photos (before accounting for the operating system and apps).

How to Do Unit Conversions (The Method)

Every unit conversion follows the same three-step process:

  1. Find the conversion factor from the charts above (or search for it).
  2. Multiply or divide your value by the conversion factor. If converting to a smaller unit (meters to centimeters), multiply. If converting to a larger unit (grams to kilograms), divide.
  3. Check the result for reasonableness. Does the answer make sense? Converting 5 miles to kilometers should give a number larger than 5 (since km are shorter than miles). If your answer is smaller, you likely divided when you should have multiplied.

Chain conversions: If you need to convert between units that are not directly in the chart, chain multiple conversions. For example, to convert 5 miles to centimeters: 5 miles → 5 × 1.60934 = 8.047 km → 8.047 × 1,000 = 8,047 m → 8,047 × 100 = 804,700 cm.

For instant results without manual calculation, use our free Unit Converter tool.


Why the US Uses a Different System

The United States is one of only three countries (along with Myanmar and Liberia) that has not officially adopted the metric system as its primary measurement standard. The US customary system evolved from British imperial units and became deeply embedded in American infrastructure, manufacturing, road signage, and daily life.

Congress actually passed the Metric Conversion Act in 1975, declaring metric as the “preferred system of weights and measures for US trade and commerce.” But the conversion was voluntary, and most industries and consumers never switched. Today, metric is used in US science, medicine, and military contexts, but imperial dominates consumer products, construction, cooking, and driving.

This is precisely why conversion charts and tools exist — and why knowing the most common conversion factors saves time in a world where both systems coexist.


FAQ

Q: What is a unit conversion chart? A: A unit conversion chart is a reference table that lists the mathematical relationships between different units of measurement. It shows you the exact factor to multiply or divide by when converting from one unit to another — such as 1 inch = 2.54 centimeters or 1 pound = 0.4536 kilograms. These charts cover categories like length, weight, volume, temperature, area, and speed.

Q: How do you convert metric to imperial? A: To convert metric to imperial, multiply the metric value by the appropriate conversion factor. For example, multiply kilograms by 2.2046 to get pounds, multiply meters by 3.2808 to get feet, or multiply liters by 0.2642 to get gallons. The key is knowing the correct conversion factor for the specific units you are working with.

Q: Is the unit converter tool free? A: Yes. The Unit Converter is completely free, works instantly in your browser, and does not require an account or login. All calculations happen on your device — no data is sent to any server.

Q: How many centimeters are in an inch? A: There are exactly 2.54 centimeters in one inch. This is an exact definition, not a rounded approximation. It was officially established in 1959 by international agreement. To convert inches to centimeters, multiply by 2.54. To convert centimeters to inches, divide by 2.54 (or multiply by 0.3937).

Q: How do you convert Fahrenheit to Celsius? A: Subtract 32 from the Fahrenheit temperature, then multiply the result by 5/9. The formula is °C = (°F - 32) × 5/9. For example, 98.6°F in Celsius is (98.6 - 32) × 5/9 = 37°C. For a quick mental estimate, subtract 30 and divide by 2 — this gives an approximate answer good enough for daily use.

Q: What is the difference between a US gallon and an imperial gallon? A: A US gallon equals 3.785 liters, while an imperial (UK) gallon equals 4.546 liters. The imperial gallon is about 20% larger. This matters when reading recipes, fuel economy figures, or product specifications from different countries. A car that gets 40 mpg in the UK gets about 33 mpg using US gallons.

Q: How many grams are in a pound? A: There are 453.592 grams in one pound. To convert pounds to grams, multiply by 453.592. To go the other way, divide grams by 453.592 (or multiply by 0.002205). A half pound is about 227 grams, which is a useful reference for cooking.


Convert Instantly

Skip the math — use our free Unit Converter

Select your input and output units, type a number, and get the result instantly. Supports length, weight, volume, temperature, area, speed, and data storage conversions.


Additional Resources

References:

  1. National Institute of Standards and Technology (NIST). “Metric System of Measurement.” https://www.nist.gov/pml/owm/metric-si
  2. International Bureau of Weights and Measures (BIPM). “The International System of Units.” https://www.bipm.org/en/measurement-units

Bookmark this page for quick reference, or use the Unit Converter for instant calculations without any manual math.

Alamzeb Khan

Written by

Alamzeb Khan

Founder, The Simple Toolbox

Alamzeb Khan is the founder of The Simple Toolbox, a collection of free, privacy-first calculators and utilities. Based in Spring, Texas.

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