Unit Converter

Unit conversion involves multiplying or applying mathematical formulas to translate measurements from one system to another. This converter uses pre-calculated conversion factors stored as JavaScript objects—for example, 1 meter = 3.28084 feet. When you input a value and select units, the tool multiplies your input by the appropriate conversion factor to calculate the result.



Temperature conversions require formulas rather than simple multiplication because Celsius, Fahrenheit, and Kelvin use different scales and zero points. The converter uses standard formulas: °F = (°C × 9/5) + 32, K = °C + 273.15. These calculations happen instantly in your browser using JavaScript functions that handle the different temperature scales mathematically.



The interface uses Svelte 5's reactive system to update all displayed conversions automatically as you type. Change the input value, and every conversion result recalculates instantly without clicking buttons. The "All Conversions" section shows simultaneous conversions to every available unit in the selected category, giving you comprehensive conversion data at a glance.

1. International Travel & Shopping
Traveling abroad requires constant unit conversions. Convert kilometers to miles for driving distances, Celsius to Fahrenheit for weather forecasts, liters to gallons for fuel consumption, and kilograms to pounds for luggage weight limits. Online shopping from international retailers needs size conversions for clothing (EU vs US sizes based on measurements).



2. Cooking & Recipe Adaptation
Recipes from different countries use various measurement systems. Convert cups to milliliters, ounces to grams, Fahrenheit to Celsius for oven temperatures. European recipes use grams and liters; American recipes use cups and tablespoons. Accurate conversions prevent cooking failures from incorrect measurements.



3. Construction & Home Improvement
DIY projects and construction require precise measurements. Convert between inches and centimeters for materials, square feet to square meters for flooring, gallons to liters for paint coverage. Buying materials online from international suppliers often requires metric-to-imperial conversions for lumber, hardware, and fixtures.



4. Fitness & Health Tracking
Fitness apps and equipment use different units. Convert miles to kilometers for running distances, pounds to kilograms for weight tracking, ounces to milliliters for hydration goals. Medical dosages may require converting between metric units. International fitness challenges often use kilometers while US users track miles.



5. Science & Engineering
STEM fields frequently require unit conversions between measurement systems. Convert meters per second to miles per hour for velocity, Celsius to Kelvin for scientific calculations, millimeters to inches for precision manufacturing. Engineering drawings may mix metric and imperial units requiring constant conversion.

• Understand precision limitations: Conversions display up to 6 decimal places, but real-world precision depends on context. For cooking, 1-2 decimals suffice. Scientific work may need 4-6. Construction tolerates 2-3. Don't over-rely on extreme precision when ±0.5% error is acceptable.



• Use the swap button for reverse conversions: Need to convert back? Click "Swap" to instantly reverse the conversion direction. Converting 100 kilometers to miles, then want miles back to kilometers? Swap instead of manually changing both dropdowns.



• Bookmark common conversions: If you frequently convert specific units (like Celsius to Fahrenheit or kilograms to pounds), note the conversion factor. 1 kg ≈ 2.2 lbs, 1 mile ≈ 1.6 km, °F = (°C × 1.8) + 32. Quick mental math for approximate conversions saves time.



• Verify critical conversions: For high-stakes situations (medical dosages, construction specs, legal compliance), verify conversions using multiple sources or calculators. Calculation errors in unit conversion have caused expensive mistakes and safety incidents historically.



• Learn metric-imperial relationships: Understanding common equivalents improves intuition. 1 inch = 2.54 cm (exact), 1 meter ≈ 3.3 feet, 1 liter ≈ 1 quart, 1 kg ≈ 2.2 lbs. Memorizing these basics makes estimation easier without calculators.



• Check temperature context: Celsius/Fahrenheit: -40° is equal in both scales, 0°C = 32°F (freezing), 100°C = 212°F (boiling). For weather, 20°C = 68°F (room temp), 30°C = 86°F (warm). Kelvin adds 273.15 to Celsius, used in scientific contexts.



• Beware of volume vs weight in cooking: Converting between volume (cups, ml) and weight (grams, oz) for ingredients isn't straightforward—density matters. 1 cup of flour ≠ 1 cup of sugar in grams. Use weight-based recipes for precision baking. This tool converts units within the same measurement type only.