Mass • NIST Exact

Pounds Kilograms

lb → kg

1 lb = 0.45359237 kgNIST Exact

lb → kg Reference Table

lb kg
0.01 lb 0.0045359237 kg
0.1 lb 0.045359237 kg
0.5 lb 0.226796185 kg
1 lb 0.45359237 kg
2 lb 0.90718474 kg
5 lb 2.26796185 kg
10 lb 4.5359237 kg
20 lb 9.0718474 kg
50 lb 22.6796185 kg
100 lb 45.359237 kg
500 lb 226.796185 kg
1000 lb 453.59237 kg

Values based on NIST SP 811 conversion factors

🌍 Real-World Examples

Average male body weight (US)

150 lb = 68.0388555 kg

Checked baggage limit (50 lb, US airlines)

50 lb = 22.6796185 kg

25 lb dumbbell (beginner weight)

25 lb = 11.33980925 kg

Standard barbell plate (45 lb)

45 lb = 20.41165665 kg

10 lb dumbbell (light training)

10 lb = 4.5359237 kg

Why Convert Pounds to Kilograms?

Converting between pounds (lb) and kilograms (kg) is one of the most common mass conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert lb to kg saves time and prevents errors.

Mass conversions between lb and kg come up constantly in everyday life. International travelers need to convert luggage weight limits — airlines typically allow 23 kg (≈50.7 lb) for checked bags and 7-10 kg for carry-on. In fitness, gym equipment in the US uses pounds while most of the world uses kilograms. Cooking recipes from different countries require converting between grams, ounces, and pounds for accurate measurements.

How to Convert Pounds to Kilograms

To convert pounds to kilograms, use the following formula:

kg = lb × 0.45359237

Example: 1 lb = 0.45359237 kg

For example, 5 lb = 2.26796185 kg, 10 lb = 4.5359237 kg, and 100 lb = 45.359237 kg. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Use Cases

  • Average male body weight (US): 150 lb = 68.0388555 kg
  • Checked baggage limit (50 lb, US airlines): 50 lb = 22.6796185 kg
  • 25 lb dumbbell (beginner weight): 25 lb = 11.33980925 kg
  • Standard barbell plate (45 lb): 45 lb = 20.41165665 kg
  • 10 lb dumbbell (light training): 10 lb = 4.5359237 kg

Common Mistakes to Avoid

  • Confusing mass and weight: In everyday use, "weight" and "mass" are interchangeable, but in science they differ. This converter handles mass units.
  • Pound ambiguity: The avoirdupois pound (lb, used for everyday weight) differs from the troy pound (used for precious metals). This converter uses avoirdupois.
  • Rounding errors in cooking: When converting lb to kg for recipes, round to the nearest practical measurement (e.g., nearest 5g or ¼ oz).

Pro Tips

  • Memorize the factor: 1 lb = 0.45359237 kg. For quick mental math, remember this base conversion.
  • Quick reference: 5 lb = 2.26796185 kg · 10 lb = 4.5359237 kg · 25 lb = 11.33980925 kg · 50 lb = 22.6796185 kg · 100 lb = 45.359237 kg
  • Bookmark this page: Save this converter for instant access. It works offline once loaded — no internet needed.

Pounds to Kilograms Conversion Table

lbkg
0.01 lb0.0045359237 kg
0.1 lb0.045359237 kg
0.5 lb0.226796185 kg
1 lb0.45359237 kg
2 lb0.90718474 kg
5 lb2.26796185 kg
10 lb4.5359237 kg
20 lb9.0718474 kg
50 lb22.6796185 kg
100 lb45.359237 kg
500 lb226.796185 kg
1000 lb453.59237 kg

All values in this table are mathematically exact per NIST SP 811.

Frequently Asked Questions

How many kilograms are in 1 pound?

1 lb equals 0.45359237 kg. This is an exact conversion factor defined by NIST.

How do I convert pounds to kilograms?

Multiply the value in lb by the conversion factor. For example, 10 lb = 4.5359237 kg. Use our calculator above for instant results.

Is the pounds to kilograms conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

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