Weight Converter

Six units, one physics

Weight talks in six everyday units — milligrams, grams, kilograms, ounces, pounds, stone — converted along the fixed scale that defines them all against the kilogram. This page walks any pair of those units through the conversion table: 1 lb is exactly 0.45359237 kg and 1 oz is exactly 28.349523125 g (both by international definitions), while 1 st is 14 lb. The tool shows six decimal places so that even small products (a 0.65 g jewellery weight to grams for a supplier quote) arrive reproducible.

Unit context matters more than the factor. Recipes live in grams and ounces; fitness scales in kilograms, pounds or stone, depending where you grew up; shipping labels stay metric almost everywhere with a US-facing pound branch. The Unit Conversion Mistakes to Avoid guide walks through why the mistakes below are as common as they are; the conversion itself is one click when you pick the correct direction.

A worked example, step by step

Problem: a friend's fitness entry says 60 kg; the US gym plan wants pounds.

1. From unit: kg (factor 1).
2. To unit: lb (factor 0.45359237 kg each).
3. Divide: 60 ÷ 0.45359237 = 132.277357 lb.
4. Practical read: about 132.3 lb — a quick mental shortcut is × 2.2, split as × 2 + × 0.2.
5. Cross-check: 60 × 2 = 120; 60 × 0.2 = 12; total 132 lb ✓.

Two more everyday directions: a 226.8 g ingredient box is 8 oz exactly (226.796185 on the tool's six decimals), and a 95 kg person to stone is 14 given the 14-lb stone — units consistent with the UK labels on bathroom scales. Contrast: converting through two roundabouts (kg → oz → g) is when rounding sneaks in; keep one-hop direct pairs wherever possible.

Anchor conversions between the six

Because lb, oz and st are defined exactly in kg, any two-hop route through kg—lb—st is leg-accurate; approximations creep in only when people round the factors first (the classic "0.45 kg per pound" habit).

From the number to the decision

The × 2.2 shortcut has earned its reputation: 60 kg × 2.2 gives 132 against the exact 132.277357 — under 0.3 lb astray, ideal for gym talk and not enough for a shipping label or an inventory line, where the tool's six-decimal output pays for itself. Mixed-unit readings deserve one extra step: a UK scale reading 11 st 2 lb converts the pounds first (2 lb = 0.907185 kg, near 0.91), then enters the kilograms total, because the tool takes one value at a time.

Consistency beats cleverness with any long dataset: pick one unit per register and let the page handle the boundaries, since a 500 g pack reads 1.10 lb in Europe and 17.64 oz in the US — the same product, one hop each way, no round-trip through kitchen intuition. Grocery labels, shipping forms and fitness apps all anchored themselves to the exact definitions above, so once the factor pair is trusted, the mental extension matters more than the arithmetic: if your daily context splits kilogram-side and pound-side, decide which source of truth to align to (typically whatever the scale or the carrier prints before doing any rounding of your own), and let the tool bridge precisely where the font switches.

Mistakes that cost grams or pounds

• Rounding the factor first. Treating lb as 0.45 kg compounds a 0.8% deficit; keep the fixed definition and round only the answer.
• Troy vs avoirdupois ounces. Bullion and pharmacy labels using troy oz are 31.1 g, different from the 28.35 kitchen ounce; this tool uses everyday avoirdupois.
• Newtons for weight. Physics and engineering also speak of weight in newtons (kg × 9.807); this page stays in mass units unless you convert the force yourself.
• Health pills with st. Stone is a display preference, not medical; practitioners log in kg and most equipment specifies metric.
• Reading 1 kg = 2 lb. Actual is 2.20462; the rounded shortcut understates conversions above 5 lb and gets worse with multiples.

Keep exploring

• Length Converter — the same thinking where the units are distances.
• Volume Converter — kitchen counterpart when the label says ml.
• Temperature Converter — the one converter that needs an offset, not just factors.
• Guide: Unit Conversion Mistakes to Avoid.