Weight & Mass Converter

A weight converter translates mass between unit systems — switching between pounds and kilograms, grams and ounces, or metric tons and pounds. This calculator normalizes every value through kilograms (the SI base unit) using exact definitions where international standards specify them.

Whether you read a gym scale in pounds but your app expects kilograms, or a recipe lists grams while your scale shows ounces, enter a value, pick From and To, and copy the result. All math stays in your browser.

The international avoirdupois pound is defined as exactly 0.45359237 kg. So one pound equals about 0.454 kg (rounded). Reverse: 1 kg ≈ 2.205 lb.

To convert pounds to kilograms, multiply pounds by 0.453592 (or divide by 2.20462). To convert kilograms to pounds, multiply kg by 2.20462.

Quick examples: 5 lb ≈ 2.27 kg · 10 lb ≈ 4.54 kg · 2 lb ≈ 0.91 kg · 6 lb ≈ 2.72 kg. Enter any number in the converter for exact figures beyond these rounded anchors.

To convert kilograms to pounds, multiply kg by 2.2046226218. Body-weight examples people look up frequently:

• 50 kg ≈ 110.2 lb
• 60 kg ≈ 132.3 lb
• 70 kg ≈ 154.3 lb
• 80 kg ≈ 176.4 lb
• 1 kg ≈ 2.205 lb · 10 kg ≈ 22.05 lb

Mid-range checks: 55 kg ≈ 121.3 lb · 62 kg ≈ 136.7 lb · 72 kg ≈ 158.7 lb · 85 kg ≈ 187.4 lb. Select Kilogram → Pound and type your value for precision beyond rounding.

US scales often read in pounds; medical and sports science increasingly uses kilograms. The same conversion factor unlocks every lookup:

• 130 lb ≈ 58.97 kg
• 150 lb ≈ 68.04 kg
• 160 lb ≈ 72.57 kg
• 165 lb ≈ 74.84 kg
• 180 lb ≈ 81.65 kg
• 190 lb ≈ 86.18 kg

Lighter entries: 20 lb ≈ 9.07 kg · 30 lb ≈ 13.61 kg · 100 lb ≈ 45.36 kg. Heavier: 175 lb ≈ 79.38 kg · 185 lb ≈ 83.91 kg. Fractional weights like 4.5 lb or 5.5 lb work the same — enter decimals in the input field.

Metric mass scales by thousands: 1 kilogram = 1,000 grams. To convert grams to kilograms, divide grams by 1,000. To convert kilograms to grams, multiply kg by 1,000.

Grams and kilograms appear in cooking, lab work, and shipping small parcels. Nutrition labels may show 2,500 g = 2.5 kg. Pick Gram or Kilogram as input — the conversion is symmetric.

One avoirdupois ounce = 28.3495 g ≈ 0.02835 kg. Sixteen ounces make one pound. To express weight in pounds and ounces from kilograms, convert kg → total pounds, then take the integer as pounds and multiply the decimal remainder by 16 for ounces.

One gram ≈ 0.002205 lb — useful for spice weights. One carat = 0.2 g (200 mg) for gemstones. One metric tonne = 1,000 kg; US short ton ≈ 907 kg; UK long ton ≈ 1,016 kg — select the correct ton type in the unit list.

Gold and silver use troy ounces (31.1035 g), not avoirdupois ounces — pick Troy Ounce when converting bullion prices.

BMI (body mass index) requires both weight and height: BMI = weight (kg) ÷ height (m)². This tool converts the weight portion — for example, 155 lb ≈ 70.3 kg before you plug into a BMI formula with height. It does not compute BMI by itself because height is required.

Convert pounds ↔ kilograms here first, then use a dedicated BMI calculator with your height in meters or centimeters.

Use avoirdupois pounds for body weight and groceries; do not mix with troy pounds (rare, used for some precious-metal trade). UK readers may think in stones (1 st = 14 lb ≈ 6.35 kg) — supported in the unit dropdown.

For shipping labels, round to the precision the carrier requires — often 0.1 kg or whole pounds. Science and medicine may need four or more decimal places; the converter shows enough digits for either. Re-check critical doses or load limits with a second unit pair (g ↔ mg) if working near thresholds.