Kilograms vs Pounds: A Complete Weight Conversion Guide

By ConvertStuffNow  ·  6 min read

Weight is one of the most frequently converted units in everyday life. A gym app that reports your lifts in pounds when you think in kilograms. A recipe that calls for "4 oz of parmesan" when your kitchen scale only shows grams. An international shipping label that needs the weight in a different unit from what your scale displays.

This guide covers everything you need to know about converting between kilograms, pounds, ounces and grams — with reference tables, the exact formulas and some mental shortcuts that are actually easy to use.

The exact conversion

One kilogram equals exactly 2.20462 pounds. One pound equals exactly 0.45359237 kilograms. These are internationally agreed definitions (the pound has been defined relative to the kilogram since 1959).

For everyday purposes, 1 kg ≈ 2.2 lb is precise enough. Going the other way, 1 lb ≈ 0.454 kg.

For ounces: 1 ounce (avoirdupois) equals 28.3495 grams. There are 16 ounces in one pound, so 1 pound = 453.592 grams.

Common kg to pounds conversions

Kilograms (kg)Pounds (lb)Pounds and ounces
1 kg2.205 lb2 lb 3.3 oz
5 kg11.02 lb11 lb 0.4 oz
10 kg22.05 lb22 lb 0.7 oz
20 kg44.09 lb44 lb 1.5 oz
50 kg110.23 lb110 lb 3.7 oz
60 kg132.28 lb132 lb 4.4 oz
70 kg154.32 lb154 lb 5.2 oz
80 kg176.37 lb176 lb 5.9 oz
90 kg198.42 lb198 lb 6.7 oz
100 kg220.46 lb220 lb 7.4 oz
120 kg264.55 lb264 lb 8.8 oz

Common pounds to kg conversions

Pounds (lb)Kilograms (kg)
1 lb0.454 kg
5 lb2.268 kg
10 lb4.536 kg
25 lb11.34 kg
50 lb22.68 kg
100 lb45.36 kg
150 lb68.04 kg
175 lb79.38 kg
200 lb90.72 kg
250 lb113.4 kg

The mental arithmetic shortcut

The exact 2.20462 multiplier is awkward for mental maths. Here are two easier approaches:

For kg to pounds: Multiply by 2 and add 10%. So 70 kg: 70 × 2 = 140, plus 10% = 14, total = 154 lb. The exact answer is 154.32 lb. For most purposes, that's close enough.

For pounds to kg: Divide by 2, then subtract 10%. So 150 lb: 150 ÷ 2 = 75, minus 10% = 7.5, total = 67.5 kg. The exact answer is 68.04 kg. Again, very close.

The reason these work is that 2.2 = 2 × 1.1, so multiplying by 2.2 is the same as multiplying by 2 and then by 1.1 (adding 10%). The reverse naturally follows.

Grams and ounces for cooking and small weights

Grams (g)Ounces (oz)
25 g0.88 oz
50 g1.76 oz
100 g3.53 oz
125 g4.41 oz
150 g5.29 oz
200 g7.05 oz
250 g8.82 oz
300 g10.58 oz
400 g14.11 oz
500 g17.64 oz

A useful rough approximation for grams to ounces: divide by 28. So 250 g ÷ 28 ≈ 8.9 oz. The exact answer is 8.82 oz.

Weight in different contexts: what unit to expect

Body weight: Kilograms are standard in most metric countries (Australia, NZ, Europe). Pounds are used in the US. The UK uses a mixture — kilograms in medical contexts, stone and pounds in everyday conversation.

Food and ingredients: Grams and kilograms are used in metric countries. US recipes use ounces and pounds. UK food is labelled in grams (by law) but older recipes may still use ounces.

Luggage: Airline baggage limits are always in kilograms, even in the US. A "23 kg checked bag allowance" is about 50 lb.

Gym and fitness: Weight plates in most countries are marked in kilograms. In the US, they're typically in pounds. Some gyms now use kilograms globally due to the international fitness industry. If you're comparing lifts with someone in another country, always check which unit they're using — a "100 lb bench press" and a "100 kg bench press" are very different things.

Need to convert between kg, pounds, ounces, grams or stone? ConvertStuffNow's weight converter handles all common weight unit conversions instantly — just type in a number.

The Troy ounce: a different kind of ounce

One important footnote: "ounce" can mean two different things. The avoirdupois ounce (used for everyday weight and food) is 28.35 grams. The troy ounce (used for precious metals — gold, silver, platinum) is 31.10 grams. If you're reading precious metal prices and the quote is "per troy ounce," that ounce is about 10% heavier than the food ounce. This rarely matters in everyday life, but it's worth knowing if you ever buy or sell bullion.

All conversion values use internationally recognised definitions based on the 1959 international yard and pound agreement. Troy ounce values are based on the troy system used in precious metal trading.