Conversion Calculator — Every Unit You Actually Need
There is a unit conversion happening somewhere every second of every day. A chef scaling a recipe from cups to milliliters. An engineer checking whether a part spec in millimeters clears a tolerance in inches. A traveler at a pharmacy who needs to know if 500 mg is the right dose. This conversion calculator handles all of it — length, temperature, area, volume, and weight — from one page, with no clutter and no waiting.
Length Converter – cm to inches, feet to meters, km to miles
The length converter covers eleven units from nanometer to light year. The numbers that come up most often: 1 inch = 2.54 cm exactly — a defined constant since 1959. 1 foot = 30.48 cm. 1 mile = 1.609344 km.
- Use centimeters to inches for clothing sizes, product dimensions, and screen diagonals
- The feet to meters calculator is standard for construction drawings and architectural specs
- Switch between kilometers and miles for running distances, driving directions, and map scales
- The mm to inches converter is used daily in machining, woodworking, and 3D printing tolerances
Temperature Converter – Celsius to Fahrenheit, Kelvin, and More
Temperature is the one conversion where a simple multiplication factor does not work. The Celsius to Fahrenheit formula is (°C × 9/5) + 32. For Celsius to Kelvin, add 273.15. Body temperature is 37°C / 98.6°F. Water freezes at 0°C / 32°F and boils at 100°C / 212°F.
Area Converter – Square Meters, Square Feet, Acres, Hectares
One square meter is 10.7639 square feet. One acre is 4,046.856 m² or exactly 43,560 square feet. One hectare is 10,000 m², which equals 2.471 acres.
Volume Converter – Liters, Gallons, Cups, mL, Fluid Ounces
One US cup is exactly 240 mL. One US gallon is 3.78541 liters. The UK Imperial gallon is 4.54609 liters — roughly 20% larger. That difference matters when comparing fuel economy between American and British vehicles.
Weight Converter – kg to lbs, Grams to Ounces, Stone to kg
One kilogram is exactly 2.20462262 pounds. One stone is 14 pounds or 6.35029 kg. Milligrams and micrograms matter for pharmaceutical dosing — a 500 mg tablet is 0.5 g.
Quick Conversion Reference
- 1 inch = 2.54 cm
- 1 foot = 30.48 cm = 12 inches
- 1 mile = 1.609344 km = 5,280 feet
- 1 kg = 2.20462 lbs = 1,000 grams
- 1 lb = 453.592 grams = 16 ounces
- 1 stone = 14 lbs = 6.35029 kg
- 1 liter = 1,000 mL = 0.264172 US gallons
- 1 US gallon = 3.78541 liters = 128 US fluid ounces
- 1 UK gallon = 4.54609 liters = 160 Imperial fluid ounces
- 1 US cup = 240 mL = 8 US fluid ounces
- 1 acre = 43,560 sq ft = 4,046.856 m²
- 1 hectare = 10,000 m² = 2.47105 acres
- 0°C = 32°F = 273.15 K
- 100°C = 212°F = 373.15 K
- 37°C = 98.6°F (normal human body temperature)
Related Calculators on AceCalculator
Unit conversion often feeds directly into a follow-on calculation. Here are the tools that pair naturally with the conversion calculator:
Frequently Asked Questions
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