Weight Converter

What this converter does

A weight converter on the public web almost always means mass. This weight converter converts mass units. It does not apply local gravity, so it will not turn kilograms into newtons. The kilogram is the base. A gram is 0.001 kg. A metric ton is 1000 kg. The pound is the international avoirdupois pound, exactly 0.45359237 kg. An ounce is 1/16 of that pound. A stone is 14 pounds. A US ton (short) is 2000 pounds. An Imperial ton (long) is 2240 pounds.

Those two tons are the usual mix-up. Shipping copy that says “ton” without a region is unfinished. This page forces the choice. It will not average them or pick the one that looks nicer. It also will not convert troy ounces. Jewelry mass is a different system.

Use this page for a kitchen scale, a shipping label, or a school conversion. Do not treat it as a density tool. It will not turn liters of water into kilograms; that would invent a density. There is no link to the volume converter for that reason. Temperature and length are different jobs.

How to use

1. Enter the mass. Commas in thousands are stripped. Scientific notation is accepted when it is a real number.
2. Choose From and To. Convert. Swap units exchanges the lists.
3. Example loads 1 kilogram to pounds. Clear empties the field.

Negative mass is rejected. Zero is allowed. Empty input and markup-looking text are errors. Labels sit above the field and the two lists. Enter converts.

Example

1 kilogram to pounds is 1 ÷ 0.45359237, about 2.20462262185 lb. 16 ounces is 1 pound. 1 US ton is 2000 lb. 1 Imperial ton is 2240 lb. 1 metric ton is 1000 kg, not 2000 lb.

1 kg = 2.20462262185 lb
16 oz = 1 lb
1 US ton = 2000 lb
1 Imperial ton = 2240 lb

Limits

• Values above 1e15 in magnitude are refused.
• Results are floating-point, then trimmed. Not legal-for-trade scale software.
• No troy, carat, or slug. No force in newtons.
• The conversion runs in this browser. Nothing is uploaded.

Write the unit next to the number. “2.2” without “lb” is not a converted mass. If the ticket said weight and the scale said kilograms, this page is the mass conversion, not a physics lecture about g.

Stone is 14 pounds, still used on some UK medical notes. Milligrams are here for labels, not for a microbalance certificate. A “tonne” in metric copy is the metric ton on this list. If the document said “ton” and the author was American, start with the US ton and then check. If the author was British and talking about ships, start with the Imperial ton. Guessing the other way and calling it close is how a shipment is booked on the wrong permit.

Bathroom scales that show both kg and lb are doing this conversion. They are not measuring two different physical quantities. This page does the same arithmetic without the scale hardware. Ounces on a kitchen scale are avoirdupois ounces here, sixteen to the pound, not fluid ounces from the volume converter.