NumberTally Unit Converter
Convert length, weight, temperature, and volume instantly. Pick a category, enter a value, choose your units — the answer updates live, with the exact conversion factor or formula shown so you can see how it works.
How temperature conversion differs
Most conversions are simple multiplications — 1 mile is always 1.60934 kilometers. Temperature is the odd one out because its scales start at different zeros: 0 °C is 32 °F, and 0 °F is −17.78 °C. So converting needs an offset plus a factor: °F = °C × 9/5 + 32, °C = (°F − 32) × 5/9, and K = °C + 273.15.
Common conversions to memorize
A few worth knowing by heart: 1 kg ≈ 2.2 lb, 1 mile ≈ 1.6 km, 1 inch = 2.54 cm exactly, 1 gallon ≈ 3.785 L, and 1 m ≈ 3.28 ft. Human body temperature 98.6 °F = 37 °C, and water freezes at 32 °F = 0 °C = 273.15 K.
Frequently Asked Questions
How many pounds are in a kilogram?
Exactly 2.2046226218 lb per kg (1 lb = 0.45359237 kg by international definition). For everyday use, 2.2 is close enough.
Why can\u2019t I convert temperature with a single multiplier?
Because Fahrenheit and Celsius have different zero points. You must add or subtract the 32-degree offset as well as multiply by 9/5 or 5/9.
What is a US ton vs a metric tonne?
The "ton" here is the US short ton of 2,000 lb (907.18 kg). A metric tonne is 1,000 kg (2,204.6 lb) — about 10% heavier.
Are US cups the same as metric cups?
No. A US cup is 236.588 mL; a metric cup is 250 mL. This converter uses the US cup, the standard for American recipes.
How precise are these conversions?
Factors use full international definitions (e.g. 1 inch = 2.54 cm exactly), so results are exact to the decimals shown — far beyond what any tape measure or kitchen scale can check.