All tools › Machines
Torque, power, rpm
Any two of the three, with both horsepowers named because they are different numbers
It runs entirely in this browser tab: the numbers you type are never uploaded, and the tool makes no network request while it works. Open your browser's network panel and try it — nothing leaves the page.
Settings
- Which horsepower
- Metric horsepower is 735.5 watts and mechanical is 745.7; neither is called just "horsepower" for that reason. Choices: Metric, Mechanical.
How to use it
- Paste your text into the box above, or open a file.
- Adjust the settings beside it until the result is what you wanted.
- Copy the result, or save it as a file. The result updates as you type.
Questions
- Can I build from this?
- Not from this alone. The cable, beam and rainwater tools each say so on their own result: they are arithmetic, and what may be built is decided by the wiring, structural and water regulations where the work is — none of which this page has read.
- Why does a tool refuse a number it could clearly calculate?
- Because several of these formulas are fits rather than laws. Wind chill is defined at 10 °C or colder in a wind over 4.8 km/h, the heat index from 27 °C up, and the barometric formula to the top of the troposphere. Outside those the arithmetic still runs and the answer means nothing, so the tool says which rather than printing it.
- Does anything here use floating point?
- No. Every figure is exact decimal arithmetic, which is why 0.1 + 0.2 is 0.3 here and a unit conversion comes back to where it started. The one place a ceiling exists — how many digits an exponent may carry — is stated rather than reached silently.
- Is what I type uploaded anywhere?
- No. This page carries the whole tool as WebAssembly and runs it on your own device. A measurement is somebody's experiment and a load is somebody's building; none of it is sent anywhere.
Other tools for machines
Gear ratio
What a train of gears does to speed and torque, stage by stage
Belt and chain length
How long a belt has to be for two pulleys at a distance, open or crossed
Beam load
Reactions, bending moment and deflection for the three standard cases
Tap drill size
The hole to drill before cutting a thread, at whatever engagement you want
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