Convert any unit instantly. Type in any field and everything updates. Covers length, weight, temperature, speed, area, volume, data, and time.
Convert between metric and imperial length units.
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Ohm's Law Calculator
Enter any two values and click Calculate to find the third. Uses W = V × A.
Ohm's Law describes the relationship between power (watts), voltage (volts), and current (amps) in an electrical circuit.
The three core values are linked by a simple triangle: W = V × A. If you know any two, you can always find the third —
which is essential for sizing fuses, choosing wire gauges, calculating battery drain, and designing circuits.
Resistance (measured in ohms, Ω) follows from V ÷ A and tells you how much a component opposes the flow of current.
Select a category using the tabs, then type a value in any field. All other units update instantly — no need to select a from/to pair.
Multiply by 9/5 then add 32. So 100°C = (100 × 9/5) + 32 = 212°F. To go the other way: subtract 32 then multiply by 5/9. This tool handles it automatically.
MB (megabyte) in decimal = 1,000,000 bytes. MiB (mebibyte) in binary = 1,048,576 bytes. Storage manufacturers use decimal, which is why a 500GB drive shows as ~465GB in Windows (which uses binary GiB). This converter includes both.
1 metre = 3.28084 feet. Conversely, 1 foot = 0.3048 metres exactly — this has been the international standard definition since 1959.
1 stone = 14 pounds = 6.35029 kg. The stone is still commonly used for body weight in the UK and Ireland, alongside kilograms.
1 knot = 1.852 km/h exactly. A knot is one nautical mile per hour. Nautical miles and knots are used in aviation and maritime navigation worldwide.
A small calorie (cal) is the energy needed to raise 1g of water by 1°C. A food Calorie (Cal or kcal) is 1,000 small calories — it's the unit on nutrition labels. So when a chocolate bar says 250 Calories, that's 250 kcal or 250,000 cal. This converter includes both, plus joules and BTUs.
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