Unit Converters
8 ToolsBasic Electrical Calculators
12 ToolsAdvanced Calculators
8 ToolsNo tools found
Try a different search term or click a category filter above.
Electrical Calculators & Unit Converters
Electrical Calculators & Unit Converters
Convert between SI and legacy units for voltage, current, power, resistance, frequency, inductance, and charge — instantly, in your browser, with no calculations to do by hand.
Who This Is For
A converter changes the scale of a number that is already known. It does not choose a wire, a breaker, or a resistor network. Volts, amps, watts, kilowatts and horsepower, frequency, inductance, charge, and ohms each cover the SI prefixes and the older unit names that still appear on drawings and in older textbooks. The ohms converter also lists the standard resistor values from IEC 60063. It does not solve Ohm's Law.
Use the search box for a name, or read how the eight fit together.
Search all KiloWattCalculator tools — or filter by category below.
Try a different search term or click a category filter above.
The volts converter, the amps converter, and the watts converter move a value across SI prefixes and the older CGS names. Use them when a drawing says millivolts, or when a datasheet says kilowatts and the next form asks for watts. The kilowatt-to-horsepower converter is the special case of power, because mechanical horsepower and metric horsepower are not the same number. Pick the horsepower the motor nameplate uses. The watts converter also keeps a closed control for specialized units such as dBm. That control stays closed until it is opened, because it is a second set of units rather than the main conversion.
The frequency converter includes revolutions per minute, because a motor speed and a line frequency are the same kind of question only after the number of poles is known. This page converts the unit. It does not compute slip or pole count. The inductance converter moves henries across prefixes and the older abhenry and stathenry names. The charge converter moves coulombs, ampere-hours, and the older electrostatic units. None of the three sizes a circuit. They make the number usable in a calculator that does.
The ohms converter takes one resistance and shows it in nanoohms through gigaohms, and in volt-per-ampere, abohm, and statohm. Under that result, the E12, E24, and E96 lists from IEC 60063 are open, so a converted number can be compared with a value that is actually sold. A 4.7 kilohm part is an E12 and an E24 value. A round 5 kilohm value is not on those two series. The nearest E24 value is 5.1 kilohm, and E96 includes 4.99 kilohm. The resistor color code decoder is the page that reads bands. This converter does not repeat that lesson.
If the unknown is voltage, current, or power in a circuit, leave this category and open the Ohm's Law calculator. If the unknown is a conductor or a breaker, open Advanced Electrical Calculators. Convert the unit first only when the source and the destination do not already share a prefix.
Milli is a thousandth. Kilo is a thousand. Mega is a million. One kilowatt is 1,000 watts. One milliamp is 0.001 amp. The converters exist so a prefix is not done from memory in the middle of another calculation. They also carry older names, such as abvolt and statampere, that a circuit calculator will not accept as an input. Convert that name into the SI unit first, then open the circuit page.
Horsepower on a motor nameplate is only a unit conversion until someone asks for wire size. After the kilowatt-to-horsepower page, the next page for a real motor is motor starting current. A resistance in kilohms is only a conversion until someone asks for current. After the ohms converter, the next page is Ohm's Law. This grid is the unit step. It is not the design.
Prefixes step by thousands: milli is one thousandth, kilo is one thousand, mega is one million. The trap on the ohms page is the letter case. A milliohm and a megohm differ by a factor of one billion. Schematics often write the prefix in place of the decimal point, under IEC 60062: 4K7 means 4.7 kilohms, and R47 means 0.47 ohm. The converter shows the spelled-out unit. Use that spelling when a drawing uses the shorthand.
EnterPlanet LLC operates the site from Jacksonville, Florida. Contact is the form if a conversion factor looks wrong.