Newtons to Poundals (N to pdl)

1 newton equals 7.233013851 poundals (rounded).

How to convert newtons to poundals

To convert newtons to poundals, multiply the number of newtons by 7.233013851. The factor is rounded to 10 significant digits. To go the other way, multiply poundals by 0.1382549544 (rounded).

poundals = newtons × 7.233013851

Example: 10 newtons = 72.33013851 poundals.

About these units

Newton (N)

Metric (SI)Current unit

The SI unit of force: the force that accelerates one kilogram by one meter per second squared. About the weight of a small apple.

Isaac Newton gave his name to the unit for his second law of motion, force equals mass times acceleration. Metric engineers needed a force unit that fitted the metre-kilogram-second system, and the CGPM standardized one in 1946; the 9th CGPM in 1948 adopted the name newton, with symbol N. Before that, many metric users measured force in kilograms-force, which confuses weight with mass, and CGS users had the much smaller dyne.

One newton is the force that gives a one-kilogram mass an acceleration of one meter per second every second. For scale, a 200-gram apple weighs about 1.96 N on Earth, so a newton is roughly the weight of a small apple. It equals 100,000 dynes and about 0.225 pound-force. Forces in the thousands are written in kilonewtons. Because the newton is built directly from kilograms, meters and seconds, it slots into formulas for pressure, energy and power without any conversion constants.

The newton is the reference unit for force on this site.

Sources: Wikipedia: Newton (unit); BIPM: 9th CGPM (1948), Resolution 7; Wikipedia: Centimetre-gram-second system of units

Poundal (pdl)

Imperial (British)Historical unit (no longer in standard use)

About 0.138255 newtons: the force that accelerates one pound by one foot per second squared. The imperial absolute unit of force.

Introduced in 1877, the poundal was built to solve a bookkeeping annoyance in the foot-pound-second system. It is the force that gives a one-pound mass an acceleration of one foot per second squared, so Newton's second law F = ma works with no extra constant. Wikipedia does not name who proposed it. The value is exactly 0.138254954376 N, derived from the international foot and pound.

Compared with the pound-force, the poundal is small, about 0.03108 of it, or roughly one thirty-second, because gravity at the surface gives 32.174 ft/s2. Its appeal is that it does not depend on gravity, so it works equally on the Moon or in deep space. A 150 lb mass accelerated at 8 ft/s2 needs 1,200 poundals, for example. The alternative cure for the same problem is the slug, a mass unit of about 32 lb used with pound-force. Both approaches saw little industrial use, and today the poundal mostly survives in textbooks and conversion tables.

1 poundal = 0.1382549544 newtons (approximately).

Sources: Wikipedia: Poundal; Wikipedia: Pound (force); NIST SP 811, Appendix B.8

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