Poundal to Newton Converter

How it is calculated

The conversion is a single multiplication or division with the fixed factor 0.138255 newtons per poundal. Poundal to newton: N = pdl × 0.138255. Newton to poundal: pdl = N / 0.138255. The direction selector decides which one is used, with poundal to newton as the default. Results are shown to 4 decimals, together with the factor itself and a line restating the pair of values. The factor follows from the definition of the poundal: 1 lb × 1 ft/s² = 0.45359237 kg × 0.3048 m/s² = 0.138254954… N, which the tool rounds to six decimals, so very large values carry a relative error of about three parts in ten million. A negative value is converted as it is, with its sign.

Common mistakes

• Choosing the wrong direction and multiplying when the value should be divided; one newton is about 7.23 poundals, not 0.138.
• Confusing the poundal with the pound-force (lbf): a pound-force is about 4.448 N, roughly 32.17 times larger than a poundal, which is why mixing them gives a huge error.
• Treating the poundal as a unit of mass; it is a unit of force, and the pound in its definition is a mass.
• Rounding the result to one or two decimals before using it further, which matters because a poundal is a small force (0.138 N).
• Reading "pdl" as a typo for "psi" or "lbs" in an old text; poundals appear only in foot-pound-second absolute-unit sources.