Unit Converter
Convert between length, weight, temperature, area, volume, speed, time, data, pressure and energy
swap_horizConversion Settings
input
Conversion Formula
Select category and units to see formula.
Result
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Quick Reference — Common Conversions
What is a Unit Converter?
A unit converter translates values between different measurement systems — from metric to imperial and vice versa. It covers all everyday measurement categories: length (km to miles), weight (kg to lbs), temperature (°C to °F), area, volume, speed, data storage, pressure, and energy.
Unit conversion is essential for international travel, scientific calculations, engineering, cooking recipes, and understanding foreign product specifications. All conversions use precise mathematical formulas to ensure accuracy across all supported units.
lightbulb Example Conversions
Scenario: Mr. Rohit, recently returned NRI from USA — needs to convert his apartment dimensions from feet/miles to metric for Indian builders: room is 12ft×10ft, house is 1,500 sq.ft, his commute was 8.5 miles, he weighs 180 lbs, oven set at 375°F
1°F = (°C × 9/5) + 32 = (100 × 1.8) + 32 = 212°F
Length: 5 km to miles
21 km = 0.621371 miles → 5 km = 3.107 miles
Weight: 70 kg to pounds
31 kg = 2.20462 lbs → 70 kg = 154.32 lbs
✓ All categories converted instantly
help_outlineHow to Use the Unit Converter
- Select the Category — choose from Length, Weight, Temperature, Area, Volume, Speed, Time, Data Storage, Pressure, or Energy.
- Enter the Value to Convert — type the number you want to convert; decimals are supported for precise measurements.
- Select the From Unit — the unit your value is currently expressed in (e.g., kilometres, Celsius, kilograms).
- Select the To Unit — the unit you want to convert to; use Swap Units to instantly reverse the direction without re-entering data.
- Click "Convert" — the result appears with the formula used; the Quick Reference table shows common conversions in that category for context.
Benefits
- Covers 10 categories and 100+ units in a single tool — no need for separate length, weight, or temperature converters
- Displays the conversion formula used — learn the relationship while getting your result
- Quick Reference table shows common conversions in the selected category for instant comparison
- Swap Units button reverses conversion instantly — no need to re-enter the value
- Supports precise scientific units (Pascal, Joule, Kelvin) alongside everyday units (kg, km, °C)
Key Terms
- SI (Metric) System
- Globally adopted system — metre, kilogram, second, kelvin as base units; used in science, medicine, and most countries including India
- Imperial System
- Inch, foot, mile, pound, Fahrenheit — used primarily in the USA; also historically used in India for land (feet, acres) and body weight (pounds)
- Conversion Factor
- The number a value must be multiplied by to convert between two units (e.g., 1 km × 0.621371 = miles)
- Absolute Temperature (Kelvin)
- Scale starting from absolute zero (0 K = −273.15°C); used in thermodynamics and gas law calculations — no negative values possible
- Binary vs SI Data Units
- 1 KB (SI) = 1,000 bytes; 1 KiB (binary) = 1,024 bytes — OS storage displays differ from manufacturer labels because of this distinction
quizFrequently Asked Questions
How do I convert temperature between Celsius, Fahrenheit, and Kelvin?
°C to °F: multiply by 9/5 then add 32. Example: 100°C = (100 × 1.8) + 32 = 212°F. °F to °C: subtract 32 then multiply by 5/9. Example: 98.6°F = (98.6 − 32) × 5/9 = 37°C (normal body temperature). °C to Kelvin: add 273.15. Example: 0°C = 273.15 K (water's freezing point). Temperature conversions involve addition/subtraction unlike length or weight which use only multiplication — this is why you can't simply apply a single factor. The converter handles all three directions automatically.
What are the most common unit conversions for everyday use in India?
Frequent conversions: 1 km = 0.621 miles (for international navigation apps); 1 kg = 2.205 lbs (travel luggage limits and fitness apps); 1 inch = 2.54 cm (clothing sizes, monitor screen sizes, pipe diameters); 1 litre = 0.264 US gallons (fuel economy comparisons with US cars); 1 acre = 4,047 m² (land measurement); °C ↔ °F (following US or UK recipes). Indian cooking often requires ml ↔ cups (1 cup = 240 ml). For property: 1 sq ft = 0.0929 m²; 1 cent = 435.6 sq ft (common in South India).
Why does my 1 TB hard drive show less than 1,000 GB in Windows?
Hard drive manufacturers use the decimal SI definition: 1 TB = 1,000 GB = 1,000,000 MB = 1,000,000,000 KB. Operating systems traditionally used binary units: 1 GiB = 1,024 MiB. So a "1 TB" (1,000,000,000,000 bytes) drive ÷ 1,024⁴ = approximately 909 GiB, which older Windows showed as "909 GB." Modern Windows 11 and macOS now report in decimal GB, reducing this confusion. When comparing storage specs, check whether the value uses base-10 (manufacturer) or base-2 (OS) measurement.
How do I convert between land area units used in Indian property transactions?
Common Indian land units: 1 acre = 43,560 sq ft = 4,047 m²; 1 guntha = 1,089 sq ft (1/40 acre); 1 cent = 435.6 sq ft (1/100 acre, common in South India); 1 bigha varies by state (e.g., UP: 2,508 m²; West Bengal: 1,337 m²; Rajasthan: 1,618 m²). For legal and registration documents, always use square metres or square feet (specified in the document) to avoid ambiguity. Traditional units like bigha differ significantly between states and are not standardised at the national level.
What pressure units does this converter support and which should I use for tyre pressure?
Supported units include Pascal (Pa), kilopascal (kPa), bar, millibar (mbar), atmosphere (atm), PSI (pounds per square inch), and mmHg. For vehicle tyres in India: car tyres typically require 30–35 PSI (≈2.0–2.4 bar); motorcycle front tyres 28–32 PSI (≈1.9–2.2 bar), rear 36–42 PSI (≈2.5–2.9 bar). Petrol station gauges in India may show PSI or kPa — 1 PSI = 6.895 kPa. For blood pressure, mmHg is standard (120/80 mmHg normal); no conversion needed for clinical use.