Power converter

Supported units are watts, kilowatts, megawatts, mechanical horsepower, BTU per hour, and foot-pounds per second, plus everyday aliases such as W, kW, MW, hp, btu/h, and ft-lb/s.

What the power converter returns and which units it understands

A power conversion answers a narrow question: given a magnitude in one unit, what is the equivalent magnitude in another unit that people actually use for motors, generators, heaters, and mechanical work. This calculator accepts a numeric value, a source unit, and a target unit, then returns the converted result rounded to a stable precision, the canonical from and to identifiers, human-readable labels, the intermediate value in watts, and the SI factors used for the bridge. Canonical ids are W for watts, kW for kilowatts, MW for megawatts, hp for mechanical horsepower, btu_h for international table BTU per hour, and ft_lb_s for foot-pounds per second. Everyday spellings such as watts, kilowatt, megawatts, horsepower, btu/h, btuh, ft-lb/s, and foot_pounds_per_second normalize to those ids so forms, query strings, and spreadsheets can reuse the same contract without inventing private enums. There is no approximate efficiency path and no fuel-consumption table: the engine either multiplies and divides by fixed factors inside the supported magnitude range or rejects the input with invalid_input. Rejected cases include missing value, from, or to; non-finite numbers; magnitudes above the documented ceiling; and any unit string that is not on the supported list.

How factors are defined and how results stay reproducible

Optional scientific notation on the value string is allowed when it parses as a finite decimal; embedded spaces, hex prefixes, and non-numeric tokens are rejected with a clear message so a bad cell does not become a wrong motor rating. Zero is a valid value and simply yields zero in the target unit. Computation multiplies value by the source factor in watts, then divides by the target factor: one kilowatt is exactly one thousand watts; one megawatt is exactly one million watts; mechanical horsepower is defined as five hundred fifty foot-pounds per second, which equals seven hundred forty-five point six nine nine eight seven one five eight two two seven zero two watts using the international foot and pound-force; one international table BTU per hour equals one thousand fifty-five point zero five five eight five two six two joules divided by three thousand six hundred seconds; one foot-pound per second equals one point three five five eight one seven nine four eight three three one four zero zero four watts. The preferred fields are value for the power magnitude, from for the source unit, and to for the target unit, with aliases amount, power, n, and quantity for the value, unit, from_unit, source, and input_unit for from, and target, to_unit, output_unit, and into for to so heterogeneous clients can share one contract. An optional precision field, with aliases decimals and dp, chooses how many decimal places to expose for value, result, and value_w, defaulting to ten and capped at fifteen so JSON goldens stay stable. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated pipeline without re-implementing unit tables yourself.

Where power conversion fits in engineering, HVAC, and software

On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split — free interactive exploration and a priced, identical API — matches the rest of the KIT tier-A catalog and lets you move from a classroom demo to an automated pipeline without changing the mathematical result.