Unit Converter

**What Is a Unit Converter and Why Does It Matter?** Converting between measurement systems is one of the most common tasks in everyday life — whether you're following a recipe from a European cookbook, planning a road trip in Canada, calculating shipping dimensions, or working on a construction project with mixed measurements. Diztool's free online unit converter handles every major unit type instantly, right in your browser, with no sign-up required. **How to Use the Unit Converter** Step 1: Select Your Category. Choose the measurement category: Length, Weight/Mass, Temperature, Volume/Capacity, Speed, Area, Energy, Pressure, Data Storage, or Time. Step 2: Enter Your Value. Type the number you want to convert — decimals (5.75 miles), large numbers (1,000,000 bytes), or small fractions (0.25 teaspoons). Step 3: Select From and To Units. Pick your source and target units. The result appears instantly. Step 4: Copy Your Result. Click the copy button or use the swap button to reverse the conversion direction. **Most-Searched Conversions (With Exact Formulas)** **Miles to Kilometers** 1 mile = 1.60934 km. Formula: km = miles × 1.60934. Example: 26.2 miles (marathon) = 42.165 km. Mental math: multiply miles by 1.6. **Pounds to Kilograms** 1 lb = 0.453592 kg. Example: 150 lbs = 68.04 kg. Mental math: divide pounds by 2.2. **Celsius to Fahrenheit** °F = (°C × 9/5) + 32. Examples: 37°C body temp = 98.6°F. 0°C freezing = 32°F. 100°C boiling = 212°F. **Fahrenheit to Celsius** °C = (°F − 32) × 5/9. Example: 72°F room temp = 22.2°C. 350°F oven = 176.7°C. **Inches to Centimeters** 1 inch = 2.54 cm (exact by international definition since 1959). Example: 6 feet = 182.88 cm. **Liters to US Gallons** 1 liter = 0.264172 US gallons. 1 US gallon = 3.78541 liters. Note: UK Imperial gallon = 4.546 liters — always specify US gallon for American use. **Feet to Meters** 1 foot = 0.3048 meters. Example: 10-foot ceiling = 3.048 meters. **Length Conversions — Reference Table** | Unit | Meters | Common Use | |---|---|---| | 1 inch | 0.0254 m | Body measurements, screen sizes | | 1 foot | 0.3048 m | Height, room dimensions | | 1 yard | 0.9144 m | Football field, fabric | | 1 mile | 1,609.344 m | Road distances (US) | | 1 cm | 0.01 m | Clothing, European dimensions | | 1 km | 1,000 m | Road distances (metric countries) | | 1 nautical mile | 1,852 m | Aviation, maritime | **Weight/Mass Conversions — Reference Table** | Unit | Grams | Common Use | |---|---|---| | 1 ounce (oz) | 28.3495 g | Food portions, USPS shipping | | 1 pound (lb) | 453.592 g | Body weight, grocery items | | 1 US short ton | 907,185 g | Construction, industrial | | 1 gram | 1 g | Cooking, lab measurements | | 1 kilogram | 1,000 g | International body weight | | 1 metric ton | 1,000,000 g | Shipping containers, cargo | **Temperature Quick Reference** | Fahrenheit | Celsius | Context | |---|---|---| | 32°F | 0°C | Water freezes | | 72°F | 22.2°C | Comfortable room temperature | | 98.6°F | 37°C | Normal body temperature | | 212°F | 100°C | Water boils (sea level) | | 350°F | 176.7°C | Baking temperature | | 450°F | 232.2°C | High-heat cooking / pizza | **Speed Conversions — Reference Table** | Unit | m/s | Common Use | |---|---|---| | 1 mph | 0.44704 m/s | US road speeds | | 1 km/h | 0.27778 m/s | International road speeds | | 1 knot | 0.51444 m/s | Aviation, maritime | | 1 m/s | 1 m/s | Physics, science | | 1 ft/s | 0.3048 m/s | Engineering | Key conversions: 60 mph = 96.56 km/h. Speed of sound = 767 mph = 1,235 km/h. Speed of light = 670,616,629 mph. **Area Conversions — Reference Table** | Unit | Square Meters | Common Use | |---|---|---| | 1 sq inch | 0.000645 m² | Small surfaces | | 1 sq foot | 0.0929 m² | Room size (US) | | 1 sq yard | 0.836 m² | Carpet, turf | | 1 acre | 4,046.86 m² | Land, real estate (US) | | 1 sq mile | 2,589,988 m² | Geographic areas | | 1 sq cm | 0.0001 m² | Small measurements | | 1 sq meter | 1 m² | Room size (metric) | | 1 hectare | 10,000 m² | Land (international) | Key: 1 acre = 43,560 sq ft. An American football field = 1.32 acres. A standard US city block ≈ 2.5 acres. **Data Storage Conversions — Reference Table** | Unit | Bytes | Common Use | |---|---|---| | 1 Byte (B) | 1 B | Single character | | 1 Kilobyte (KB) | 1,024 B | Small text file | | 1 Megabyte (MB) | 1,048,576 B | Photo, song | | 1 Gigabyte (GB) | 1,073,741,824 B | Movie, app | | 1 Terabyte (TB) | ~1.1 trillion B | Hard drive | | 1 Petabyte (PB) | ~1.1 quadrillion B | Data centers | Key: A typical smartphone photo = 3–8 MB. A 4K movie = 50–100 GB. 1 TB = 1,024 GB. A 256 GB iPhone holds roughly 50,000 photos. Note: Storage manufacturers use decimal (1 KB = 1,000 B) while operating systems use binary (1 KB = 1,024 B), which is why a "256 GB" drive shows as ~238 GB on your computer. **Energy Conversions** | Unit | Joules | Common Use | |---|---|---| | 1 calorie (cal) | 4.184 J | Small food energy unit | | 1 Calorie (kcal) | 4,184 J | Nutrition labels (US) | | 1 kilowatt-hour (kWh) | 3,600,000 J | Electricity bills | | 1 BTU | 1,055 J | HVAC, heating fuel (US) | | 1 joule | 1 J | Physics SI unit | Key: A food Calorie (with capital C) = 1 kilocalorie = 1,000 small calories. A 2,000 calorie diet = 2,000 kcal = 8,368,000 joules. Average US electricity cost: ~$0.16 per kWh. **Pressure Conversions** | Unit | Pascals | Common Use | |---|---|---| | 1 PSI | 6,894.76 Pa | Tire pressure (US) | | 1 bar | 100,000 Pa | Weather, industrial | | 1 atmosphere (atm) | 101,325 Pa | Standard air pressure | | 1 mmHg (torr) | 133.322 Pa | Blood pressure | | 1 Pascal (Pa) | 1 Pa | SI unit | Key: US car tire pressure = 30–35 PSI. Blood pressure: normal = 120/80 mmHg. A bar = 14.504 PSI. Standard atmosphere = 14.696 PSI. **US Customary vs. Metric System — Why Two Systems Exist** The United States is one of only three countries (with Myanmar and Liberia) not using SI as its primary system. The US customary system evolved from British Imperial units with some differences (notably, US liquid gallon ≠ Imperial gallon). Where metric is already standard in the US: medicine (mg, mL, kg), science, military, nutrition labels (grams), photography (35mm lenses), and alcohol (750 mL bottles). NIST officially recognizes both systems. **Real-World Use Cases by Industry** **Cooking and Baking** European recipes use grams and mL; US recipes use cups, ounces, and Fahrenheit. 1 cup = 236.6 mL. 1 tablespoon = 14.79 mL. 1 US fluid ounce = 29.57 mL. Oven temperatures: 350°F = 176.7°C = Gas Mark 4 (UK). **Fitness and Health** BMI requires kg and meters. A 5'10" 175 lb American = 177.8 cm, 79.4 kg. Drug dosing in hospitals uses mg/kg body weight — your chart is always in metric. **Travel** Canada: 100 km/h ≈ 62 mph. European gas: ~$2.00/L = ~$7.57/gallon equivalent. Hotel temperatures in Celsius: 22°C = 71.6°F. **Construction** US lumber sold in feet/inches; European fixtures use mm. A 2×4 stud is actually 1.5" × 3.5" = 38mm × 89mm. Tile: 12×12 inch = 30×30 cm. **Shipping and E-Commerce** International shipments require kg and cm. 1 lb = 0.4536 kg. 1 inch = 2.54 cm. USPS cubic pricing uses inches; DHL uses cm. **Fuel Efficiency** mpg (US) ↔ L/100km: mpg = 235.21 ÷ (L/100km). A 30 mpg car = 7.84 L/100km. Note: UK mpg uses Imperial gallons — a British "40 mpg" = 33.3 US mpg. **Mental Math Tricks for Quick Estimates** - Miles → km: multiply by 1.6 (exact: 1.60934) - kg → lbs: multiply by 2.2 (exact: 2.20462) - °C → °F: double and add 30 (exact formula: ×1.8+32) - Liters → gallons: divide by 3.8 (exact: 3.78541) - cm → inches: divide by 2.54 (exact) - meters → feet: multiply by 3.28 (exact: 3.28084) - GB → MB: multiply by 1,024 - ounces → grams: multiply by 28 (exact: 28.3495) **5 Common Conversion Mistakes (and Their Consequences)** 1. **US gallons vs. Imperial gallons.** US gallon = 3.785 liters. UK gallon = 4.546 liters. A fuel pump rated for 50 Imperial gal/min delivers 41.6 US gallons — a 20% miscalculation. 2. **Short ton vs. metric ton.** US short ton = 2,000 lbs = 907 kg. Metric ton = 1,000 kg = 2,205 lbs. On commodity contracts, mixing these creates a 10% discrepancy. 3. **Fluid ounces ≠ weight ounces.** 1 fl oz of water ≈ 1.04 oz by weight. 1 fl oz of honey ≈ 1.5 oz by weight. Volume and mass are equal only when density = 1 g/mL. 4. **Celsius when Kelvin is required.** Thermodynamic formulas use Kelvin. At 25°C, K = 25 + 273.15 = 298.15 K. Using Celsius directly in gas law calculations produces wrong results. 5. **Storage decimal vs. binary prefixes.** Manufacturers use 1 GB = 1,000,000,000 bytes; OSes use 1 GB = 1,073,741,824 bytes. A "1 TB" drive shows as 931 GB on your computer — this is expected, not a defect. **Pro Tips** - Professional chefs weigh in grams (not cups) for consistency — weight is unaffected by how packed ingredients are - For international project specs, always convert to the measurement system of the final manufactured part to avoid tolerance stack-up errors - When comparing fuel efficiency internationally, always specify US mpg vs. UK mpg — they differ by 20%