Result
This page has no server side at all. The table you paste is parsed by JavaScript inside your own browser, the chart is drawn on a canvas element on your machine, and the export file is assembled locally. Nothing is uploaded, stored or written to any log. You can disconnect from the network after the page has loaded and everything will still work — which is the simplest way to verify the claim yourself.
Facts and limits of this method
| Base unit | Watt — all other units convert through it |
|---|---|
| 1 mechanical hp | ≈745.699872 W (used in the US and UK) |
| 1 metric hp (PS) | 735.49875 W (used in Russia, Europe and most of the world) |
| 1 BTU/h | ≈0.293071 W (British thermal unit per hour) |
| 1 kcal/h | 1.163 W |
| Total units | 7 — W, kW, MW, hp, PS, BTU/h, kcal/h |
When it misleads you
- The calculation happens in two steps: the value is first converted to watts, then from watts to the target unit, so choosing the same unit for "from" and "to" leaves the result unchanged.
- Mechanical ("imperial", hp) and metric (PS) horsepower are different units: metric is about 1.4% smaller than mechanical — when reading an engine's power figure, it matters which one the source uses.
- BTU per hour is commonly used for heating and air conditioning system power in the US — don't confuse it with BTU as a plain unit of energy (with no time dimension).
- Rounding is applied only to the displayed result — internal calculations use the full precision of JavaScript floating-point numbers.
How it is calculated
Each of the seven units has a preset conversion factor to watts — for example, 1 metric hp = 735.49875 W, 1 mechanical hp ≈ 745.699872 W.
The entered value is multiplied by the factor of the selected "from" unit, giving power in watts.
The power in watts is divided by the factor of the "to" unit, giving the result in the target unit.
The result is rounded to the chosen number of decimal places and updates instantly whenever the value, units or precision change.
Questions and answers
How is metric horsepower different from mechanical horsepower?
These are different units: metric hp (PS) = 735.49875 W, mechanical hp (used in English-speaking countries) ≈ 745.699872 W — mechanical is about 1.4% larger.
Which horsepower is used for cars in Russia and Europe?
Usually metric horsepower (PS, CV, l.s.) — if a spec sheet lists power in hp from a US or UK source, it's worth converting separately.
What is BTU per hour?
A unit of thermal power common in the US for air conditioners and heaters — 1 BTU/h ≈ 0.293071 W.
Is my data sent anywhere?
No, the whole calculation runs in your browser.