📐 Unit Converter

1. Select the category of measurement you want to convert — length, weight, temperature, volume, area, speed, or time.
2. Choose the source unit (the unit your original value is in) and the target unit (the unit you want to convert to).
3. Enter the value you want to convert in the input field.
4. The converted result appears instantly as you type, with no need to press a calculate button. You can switch between categories or change units at any time. For temperature conversions, the tool handles the offset formula automatically — simply enter the value and select the units. For repeated conversions, the tool remembers your last-used category and units for convenience.

Why does the United States still use the imperial system?

The U.S. adopted the customary system (closely related to the British Imperial system) before the metric system existed and simply never switched. The Metric Conversion Act of 1975 made metric the preferred system, but compliance was voluntary, and public resistance prevented a full transition. Today, U.S. industries like automotive, pharmaceuticals, and science already use metric internally, but consumer-facing measurements remain imperial for historical and cultural reasons. Only three countries — the U.S., Liberia, and Myanmar — have not officially adopted the metric system as their primary standard.

How do I convert cooking measurements?

Common cooking conversions include: 1 cup = 240 ml (or 237 ml by U.S. legal standard), 1 tablespoon = 15 ml, 1 teaspoon = 5 ml, 1 ounce = 28.35 grams, and 1 pound = 453.6 grams. Note that U.S. cups differ slightly from metric cups (250 ml used in Australia, Canada, and the UK). When following international recipes, always check which cup standard the recipe uses, as the difference can affect baking results.

What is an easy trick for Celsius to Fahrenheit?

For a quick mental estimate, double the Celsius temperature and add 30. This gives a close approximation for everyday temperatures: 20°C × 2 + 30 = 70°F (actual is 68°F). For exact conversion, use the formula °F = (°C × 9/5) + 32. A few reference points help: 0°C = 32°F (freezing), 10°C = 50°F (cool), 20°C = 68°F (room temperature), 30°C = 86°F (hot), 40°C = 104°F (very hot).

What is the difference between mass and weight?

Mass measures the amount of matter in an object and stays constant regardless of location. Weight is the force of gravity acting on that mass. A 70 kg person has the same mass on Earth and on the Moon, but weighs about one-sixth as much on the Moon due to lower gravity. In everyday usage, kilograms and pounds are treated as interchangeable mass units, though pounds are technically a unit of force.

Memorize a few key reference conversions for everyday use: 1 inch ≈ 2.5 cm, 1 kg ≈ 2.2 lb, 1 mile ≈ 1.6 km, and 1 liter ≈ 1 quart (slightly more, actually 1.057 quarts). These four cover most daily conversion needs without a tool. When cooking, note that U.S. measuring cups (237 ml) differ from metric cups (250 ml), which can affect baking precision — always verify the recipe's origin. For travel, remember that speed limits in most countries are in km/h, so multiply by 0.621 to get mph (100 km/h ≈ 62 mph). For scientific work, always use SI units and convert at the end to avoid compounding rounding errors. Be aware that fluid ounces differ between the U.S. (29.57 ml) and imperial (28.41 ml) systems — a subtle but important distinction for beverage and recipe measurements. When shopping internationally for clothing or shoes, always check the specific country's sizing chart, as there is no universal standard and conversions vary by brand.