Pound (lb) and Kilograms (Kg) Conversion Calculator

An online lb (pound) and Kg (kilogram) conversion calculator is presented along with conversion formulas, step-by-step examples, and practical word problems.

Abbreviations:

Conversion Formula of Pound into Kg [1]

By international agreement:

\[ 1 \text{ lb} = 0.45359237 \text{ Kg} \] \[ 1 \text{ Kg} = \left(\frac{1}{0.45359237}\right) \text{ lb} \approx 2.20462262185 \text{ lb} \]

Reference: NIST Reference Guidelines

Examples of Conversion

Example 1

Convert \( 12.5 \, \text{lb} \) into Kg and round the answer to 1 decimal place.

View Solution
\[ 12.5 \, \text{lb} = 12.5 \times 0.45359237 \, \text{Kg} \approx 5.669904625 \, \text{Kg} \]

Rounding to 1 decimal place gives:

\[ 5.7 \, \text{Kg} \]

Example 2

Convert \( 1.56 \, \text{kg} \) into lb and round the answer to 1 decimal place.

View Solution
\[ 1.56 \, \text{kg} = 1.56 \times 2.20462262185 \, \text{lb} \approx 3.43921129 \, \text{lb} \]

Rounding to 1 decimal place gives:

\[ 3.4 \, \text{lb} \]

Use of lb and kg Conversion Calculators

Enter the number of pounds (lb) or kilograms (kg) to be converted and calculate.

lb         kg
kg         lb
Decimal Places

Problems Involving lb and Kg Conversions

Problem 1

A cow consumes 2% of its body weight daily. How many days will \( 10,000 \, \text{Kg} \) of cow feed last for a cow whose weight is \( 1,600 \, \text{lb} \)? Round your answer to the nearest whole number.

View Solution

Let \( W \) be 2% of the body weight of the cow:

\[ W = 2\% \times 1600 \, \text{lb} = 32 \, \text{lb} \]

Convert the available cow feed to pounds:

\[ 10,000 \, \text{Kg} = 10,000 \times 2.20462262185 \, \text{lb} \approx 22,046.2262185 \, \text{lb} \]

The number \( N \) of days the feed will last is:

\[ N = \dfrac{22,046.2262185 \, \text{lb}}{32 \, \text{lb}} \approx 688.944569 \, \text{days} \]

Rounding to the nearest whole number of days:

\[ N = 689 \text{ days} \]

Problem 2

A restaurant uses \( 5 \, \text{Kg} \) of potatoes and \( 2 \, \text{Kg} \) of carrots every day. Potatoes are sold in bags of \( 5 \, \text{lb} \) and carrots in bags of \( 0.5 \, \text{lb} \). A bag of potatoes costs $7 and a bag of carrots costs $3. How much does this restaurant spend on potatoes and carrots in 30 days?

View Solution

In 30 days, the total potatoes used:

\[ 30 \times 5 \, \text{Kg} = 150 \, \text{Kg} \]

Convert \( 150 \, \text{Kg} \) into pounds:

\[ 150 \, \text{Kg} = 150 \times 2.20462262185 \, \text{lb} \approx 330.693393 \, \text{lb} \]

Number \( N_1 \) of potato bags needed (rounded up to the next higher whole number):

\[ N_1 = \dfrac{330.693393}{5} \approx 66.1387 \implies 67 \text{ bags} \]

In 30 days, the total carrots used:

\[ 30 \times 2 \, \text{Kg} = 60 \, \text{Kg} \]

Convert \( 60 \, \text{Kg} \) into pounds:

\[ 60 \, \text{Kg} = 60 \times 2.20462262185 \, \text{lb} \approx 132.277357 \, \text{lb} \]

Number \( N_2 \) of carrot bags needed (rounded up to the next higher whole number):

\[ N_2 = \dfrac{132.277357}{0.5} \approx 264.5547 \implies 265 \text{ bags} \]

Total cost \( C \) for 30 days:

\[ C = 67 \times \$7 + 265 \times \$3 = \$469 + \$795 = \$1,264 \]

Problem 3

One pound of boneless chicken costs $10. How much does a kilogram of boneless chicken cost?

View Solution

Convert the unit cost from per pound to per kilogram:

\[ \$10 / \text{pound} = \dfrac{\$10}{0.45359237 \, \text{Kg}} \approx \$22.046226 \, \text{Kg} \]

Rounding to the nearest cent gives:

\[ \$22.05 / \text{kg} \]

More References and Links

  1. NIST Reference Guidelines
  2. Units Conversion and Calculators
  3. Math Calculators and Solvers
  4. Home Page