Using this conversion calculator
This tool converts between the most searched everyday units — meters and feet, Celsius and Fahrenheit, square meters and acres, liters and gallons, kilograms and pounds. Choose a category tab, type a value in From, select your units, and read the result immediately. A full equivalence table lists every unit in that category so you can compare multiple targets without retyping.
- Pick a category — Length, Temperature, Area, Volume, or Weight.
- Enter a value in the From field (for example, 100 meters).
- Select units in the From and To dropdowns.
- Swap — click the circular arrow to flip units and values.
- Save — click Calculate, then Save to store the result in your browser.
For popular searches like “cm to inches,” “kg to lbs,” or “C to F,” read our Conversion Calculator guide with formulas, metric vs imperial tips, and worked examples.
What units can I convert?
| Category | Common units included | Popular searches |
|---|---|---|
| Length | Meter, kilometer, centimeter, mile, yard, foot, inch, light year | m to ft, cm to in, km to miles |
| Temperature | Celsius, Fahrenheit, Kelvin | C to F, F to C, oven temps |
| Area | Square meter, hectare, acre, square foot, square inch | sq m to sq ft, acres to hectares |
| Volume | Liter, milliliter, US & imperial gallons, cups, cubic feet | liters to gallons, ml to oz, cubic feet |
| Weight | Kilogram, gram, pound, ounce, metric ton | kg to lbs, grams to oz, stones alternative |
How unit conversion works
Most units in this calculator are linear: each unit has a fixed ratio to a base unit (meter for length, kilogram for weight, and so on). To convert, the tool first expresses your input in the base unit, then divides by the target unit’s ratio.
Temperature is different. Celsius, Fahrenheit, and Kelvin use offset formulas, not simple multiplication. The calculator applies the standard science formulas:
Metric vs imperial — when each system matters
The metric system (SI) uses powers of ten — centimeters per meter, milliliters per liter — which makes science and international trade straightforward. The US customary and imperial systems (feet, pounds, gallons) remain common in American construction, recipes, and road signs. A conversion calculator bridges both so you can read a European recipe in US cups or compare a 5K race distance to miles without mental arithmetic errors.
Need percentage math alongside measurements? Try our Percentage Calculator or Percent Off Calculator for discounts and markups. For body-weight context after converting kg to lbs, see the BMI Calculator. For date-based calculations, use the Age Calculator.
Length conversions
Length is the most searched conversion category worldwide. Quick references people look up daily:
- 1 meter ≈ 3.281 feet
- 1 inch = 2.54 centimeters (exact by international definition)
- 1 mile ≈ 1.609 kilometers
- 1 yard = 3 feet = 0.9144 meters
Enter any value and the equivalence table shows centimeters, millimeters, micrometers, nanometers, miles, yards, feet, inches, and light years from the same input — useful for homework, engineering sketches, and travel planning.
Temperature conversions
Weather forecasts, oven settings, and science labs use different scales. Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F). Absolute zero is −273.15 °C or 0 K. Body temperature is about 37 °C or 98.6 °F. Select Celsius, Fahrenheit, or Kelvin and convert in either direction.
Area and volume for real estate, gardening, and cooking
Area conversions help when floor plans list square feet but materials are sold per square meter, or when comparing land in acres vs hectares. Volume conversions matter for fuel tanks (gallons vs liters), concrete pours (cubic yards vs cubic meters), and kitchen measuring cups (US vs imperial fluid ounces differ slightly). For shipping cartons and freight quotes, use our CBM Calculator to multiply length × width × height into cubic meters and volumetric weight.
Weight and mass
Everyday “weight” conversions — pounds to kilograms for luggage limits, ounces to grams for baking, metric tons for shipping — use the kilogram as the base unit. Note that mass and weight differ in physics (weight depends on gravity), but colloquially people search “weight converter” for mass units, which is what this tool provides.
Examples and use cases
Worked example
Convert 100 kilometers to miles:
- 100 km ÷ 1.609344 ≈ 62.14 miles
- Reverse: 62.14 mi × 1.609344 ≈ 100 km
Real-world use cases
- Recipe scaling: A baker converts 500 grams of flour to ounces for a US cookbook that lists imperial weights.
- Travel luggage: A flyer checks whether a 23 kg bag limit equals roughly 50.7 lbs before heading to the airport.
- Home renovation: A DIYer converts 12 feet of lumber to centimeters to match a European hardware catalog listing.
Accuracy and limitations
Conversion factors match standard definitions used in science and engineering (for example, 1 inch = 2.54 cm exactly). Results display up to 12 significant digits; very large values (light years) or tiny values (atomic mass units) may use scientific notation. This tool is for education and everyday use — verify critical measurements (medical doses, aviation fuel, structural loads) against authoritative sources.