How to convert pounds-force to newtons
Multiply the value in pounds-force by 4.4482. The hard part is not the arithmetic but the reading: an American datasheet often writes lb for a force as well as for a mass, and only the surrounding sentence says which one is meant.
lbf = N ÷ 4.4482
Everyday forces in pounds-force and in newtons
| 1 lbf | 4.45 N |
| 2 lbf | 8.90 N |
| 5 lbf (door) | 22.24 N |
| 10 lbf | 44.48 N |
| 20 lbf | 88.96 N |
| 40 lbf (bow) | 177.93 N |
| 50 lbf | 222.41 N |
| 100 lbf | 444.82 N |
| 500 lbf | 2,224.11 N |
| 1,000 lbf | 4,448.22 N |
| 5,000 lbf | 22,241.11 N |
Show every value
- 1 lbf = 4.448 N
- 2 lbf = 8.896 N
- 3 lbf = 13.345 N
- 4 lbf = 17.793 N
- 5 lbf = 22.241 N
- 6 lbf = 26.689 N
- 7 lbf = 31.138 N
- 8 lbf = 35.586 N
- 9 lbf = 40.034 N
- 10 lbf = 44.482 N
- 11 lbf = 48.93 N
- 12 lbf = 53.379 N
- 13 lbf = 57.827 N
- 14 lbf = 62.275 N
- 15 lbf = 66.723 N
- 16 lbf = 71.172 N
- 17 lbf = 75.62 N
- 18 lbf = 80.068 N
- 19 lbf = 84.516 N
- 20 lbf = 88.964 N
- 21 lbf = 93.413 N
- 22 lbf = 97.861 N
- 23 lbf = 102.309 N
- 24 lbf = 106.757 N
- 25 lbf = 111.206 N
- 26 lbf = 115.654 N
- 27 lbf = 120.102 N
- 28 lbf = 124.55 N
- 29 lbf = 128.998 N
- 30 lbf = 133.447 N
- 31 lbf = 137.895 N
- 32 lbf = 142.343 N
- 33 lbf = 146.791 N
- 34 lbf = 151.24 N
- 35 lbf = 155.688 N
- 36 lbf = 160.136 N
- 37 lbf = 164.584 N
- 38 lbf = 169.032 N
- 39 lbf = 173.481 N
- 40 lbf = 177.929 N
- 41 lbf = 182.377 N
- 42 lbf = 186.825 N
- 43 lbf = 191.274 N
- 44 lbf = 195.722 N
- 45 lbf = 200.17 N
- 46 lbf = 204.618 N
- 47 lbf = 209.066 N
- 48 lbf = 213.515 N
- 49 lbf = 217.963 N
- 50 lbf = 222.411 N
- 51 lbf = 226.859 N
- 52 lbf = 231.308 N
- 53 lbf = 235.756 N
- 54 lbf = 240.204 N
- 55 lbf = 244.652 N
- 56 lbf = 249.1 N
- 57 lbf = 253.549 N
- 58 lbf = 257.997 N
- 59 lbf = 262.445 N
- 60 lbf = 266.893 N
- 61 lbf = 271.342 N
- 62 lbf = 275.79 N
- 63 lbf = 280.238 N
- 64 lbf = 284.686 N
- 65 lbf = 289.134 N
- 66 lbf = 293.583 N
- 67 lbf = 298.031 N
- 68 lbf = 302.479 N
- 69 lbf = 306.927 N
- 70 lbf = 311.376 N
- 71 lbf = 315.824 N
- 72 lbf = 320.272 N
- 73 lbf = 324.72 N
- 74 lbf = 329.168 N
- 75 lbf = 333.617 N
- 76 lbf = 338.065 N
- 77 lbf = 342.513 N
- 78 lbf = 346.961 N
- 79 lbf = 351.41 N
- 80 lbf = 355.858 N
- 81 lbf = 360.306 N
- 82 lbf = 364.754 N
- 83 lbf = 369.202 N
- 84 lbf = 373.651 N
- 85 lbf = 378.099 N
- 86 lbf = 382.547 N
- 87 lbf = 386.995 N
- 88 lbf = 391.444 N
- 89 lbf = 395.892 N
- 90 lbf = 400.34 N
- 91 lbf = 404.788 N
- 92 lbf = 409.236 N
- 93 lbf = 413.685 N
- 94 lbf = 418.133 N
- 95 lbf = 422.581 N
- 96 lbf = 427.029 N
- 97 lbf = 431.477 N
- 98 lbf = 435.926 N
- 99 lbf = 440.374 N
- 100 lbf = 444.822 N
- 125 lbf = 556.028 N
- 150 lbf = 667.233 N
- 175 lbf = 778.439 N
- 200 lbf = 889.644 N
- 225 lbf = 1,000.85 N
- 250 lbf = 1,112.055 N
- 275 lbf = 1,223.261 N
- 300 lbf = 1,334.466 N
- 325 lbf = 1,445.672 N
- 350 lbf = 1,556.878 N
- 375 lbf = 1,668.083 N
- 400 lbf = 1,779.289 N
- 425 lbf = 1,890.494 N
- 450 lbf = 2,001.7 N
- 475 lbf = 2,112.905 N
- 500 lbf = 2,224.111 N
- 550 lbf = 2,446.522 N
- 600 lbf = 2,668.933 N
- 650 lbf = 2,891.344 N
- 700 lbf = 3,113.755 N
- 750 lbf = 3,336.166 N
- 800 lbf = 3,558.577 N
- 850 lbf = 3,780.988 N
- 900 lbf = 4,003.399 N
- 950 lbf = 4,225.811 N
- 1,000 lbf = 4,448.222 N
- 1,500 lbf = 6,672.332 N
- 2,000 lbf = 8,896.443 N
- 2,500 lbf = 11,120.554 N
- 3,000 lbf = 13,344.665 N
- 3,500 lbf = 15,568.776 N
- 4,000 lbf = 17,792.886 N
- 4,500 lbf = 20,016.997 N
- 5,000 lbf = 22,241.108 N
- 5,500 lbf = 24,465.219 N
- 6,000 lbf = 26,689.33 N
- 6,500 lbf = 28,913.44 N
- 7,000 lbf = 31,137.551 N
- 7,500 lbf = 33,361.662 N
- 8,000 lbf = 35,585.773 N
- 8,500 lbf = 37,809.884 N
- 9,000 lbf = 40,033.995 N
- 9,500 lbf = 42,258.105 N
- 10,000 lbf = 44,482.216 N
The factor comes from two exact definitions, the pound at 0.45359237 kilogram and standard gravity at 9.80665 metres per second squared, fixed by the 3rd General Conference on Weights and Measures in 1901. Their product is 4.4482216152605 newtons, with no rounding. Methodology & sources.
Frequently asked questions
What is the difference between lb and lbf?
The pound is a mass, the pound-force is the weight of that mass under standard gravity. One pound is exactly 0.45359237 kilogram and one pound-force is exactly 4.4482216152605 newtons. American datasheets often write lb for both, sometimes lbm for the mass and lbf for the force, and only the surrounding sentence tells you which is meant.
What are the slug and the poundal?
Two ways of making mechanics consistent while counting in feet and pounds. The slug is the mass that one pound-force accelerates at one foot per second squared: it weighs 14.5939 kilograms, or 32.174 pounds. The poundal does the opposite, it is the force that accelerates one pound at one foot per second squared, and it is only 0.1383 newton. American engineering often keeps the pound on both sides instead and carries a constant, written gc, equal to 32.174.
What does a sling rated 4,000 lb actually hold?
That figure is a working load limit, not a breaking strength. American lifting gear carries its WLL in pounds and ASME B30.9 requires a design factor of 5 for a synthetic web sling: failure therefore comes near 20,000 pounds, or 89 kilonewtons. The European standard EN 1492 uses a factor of 7 and prints the same information in kilograms, so two labels cannot be compared without converting the factor as well.
Does a magnet rated at 50 pounds really hold 50 pounds?
Rarely. The quoted pull force, 50 pounds or 222 newtons, is measured under ideal conditions: direct contact with no paint or gap, a thick mild steel plate, and a pull perpendicular to the surface. Thin sheet metal, a coat of paint or a peeling angle cut the figure by half or more, and resistance to sideways sliding is only a fraction of the rated pull.
How are forces smaller than a pound written?
In ounces-force, grams-force or centinewtons. One ounce-force is 0.2780 newton and one gram-force is 0.00980665 newton. This is the language of small mechanisms: a mechanical keyboard switch is specified at 45 grams-force, that is 0.44 newton or 1.6 ounce-force, and the same units serve springs, microswitches and peel tests.