Weight & Mass Converter

Convert between kilograms, pounds, ounces, grams, and other weight units.

How to Use Weight & Mass Converter

1

Enter a value

Type the weight or mass measurement to convert.
2

Select source unit

Choose kilograms, pounds, ounces, grams, or another unit.
3

View the conversion

See the weight converted to all available units instantly.

Tested tool guide Tested browser tools Checked August 16, 2026

What Weight & Mass Converter does, with a checked example

Kilograms and pounds do not divide evenly, which is why this converter exists: one kilogram is 2.2046226 pounds, so a 75 kg weight reads as 165.35 lb, not the 150 lb an even split would suggest. The tool converts between grams, kilograms, ounces, pounds, and other units in both directions, working from the exact defining value of each unit (one international pound is exactly 453.59237 g) rather than the common 2.2 shortcut. The mistake people make most often is picking the wrong ounce or ton, because precious metals and shipping use different units than everyday cooking weights.

Worked example

A concrete input and expected output from the current implementation.

Input

75 kg

Expected output

165.35 lb

One kilogram is 2.2046226218 lb, and 75 x 2.2046226218 = 165.3467, which rounds to 165.35. Converting back by dividing gives 165.35 / 2.2046226218 = 75.00 kg, so the two directions reconcile.

How the result is produced

Conversions run through the gram

Every unit has a fixed defining relationship to the gram, so a conversion is a single multiplication or division. One pound is defined as exactly 453.59237 g by the 1959 international agreement, one ounce is one sixteenth of that at 28.349523125 g, and one kilogram is exactly 1,000 g. Because these are definitions rather than measurements, the same input always gives the same output, with no lookup table required.

The two directions are exact inverses

Converting kg to lb multiplies by 2.2046226; converting lb to kg divides by the same factor, so the pair always reconciles apart from display rounding. Cross-checking is easy: 5 kg becomes 11.02 lb (5 x 2.2046226218 = 11.0231131), and converting 11.02 lb back returns about 5.00 kg. If a round trip drifts, the cause is rounding in the middle step, not the conversion itself.

Good uses

Baking or cooking with a recipe in pounds and ounces while your scale reads grams: 1 lb 8 oz of flour is exactly 680.39 g.
Stating a body weight in the system your audience uses: 75 kg is 165.35 lb, or 11 st 11 lb.
Checking a luggage or shipping limit quoted in kg when your home scale shows pounds, or the reverse.

Limits and checks

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Common questions

How accurate is the multiply-by-2.2 shortcut?

It is about 0.2% low: 75 kg x 2.2 gives 165 lb against a true 165.35 lb, a difference of roughly 2 g per kilogram. Fine for a conversation, wrong for a parcel or anything measured against a limit. Use the exact factor of 2.2046226 whenever the number will be acted on.

Why is my bathroom scale result different from the conversion?

Consumer scales measure weight under Earth's gravity and round to increments of 0.1 kg or 0.2 lb, so readings drift by a few tenths even when calibrated. The converter is exact but works on the number you type, not the number the scale actually measures, so enter the raw reading to compare fairly.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.