Convert metric mass and avoirdupois pounds

Each unit has a factor to the kilogram. Convert to kg, then to the target. The tonne offered is the metric ton (1,000 kg), not the US short ton (2,000 lb) or the UK long ton. The ounce is the avoirdupois ounce (1/16 of a pound), not the troy ounce of gold. A force in newtons (W = m g) is not computed: g varies and is not asked.

m(kg) = x × kfrom ; y = m(kg) / kto

1 lb = 0,45359237 kg

1 oz = 1 lb / 16 = 0,028349523125 kg

The kilogram is the SI unit of mass (BIPM). Avoirdupois factors are NIST’s, exact by definition. Converting a bathroom-scale “weight” is converting a mass if the scale is in kg or lb of mass. A reading in newtons would be a force; it has no place here. The tonne (t) in common SI use is 1,000 kg.

Value

A negative number is mathematically accepted; a negative physical mass has no everyday meaning.

From

mg, g, kg, metric t, oz and lb avoirdupois.

To

Same list. For a US short ton, that is not “t”: 1 short ton = 2,000 lb, convert in two steps via lb.

Assumptions

• We convert a mass, not a force.
• lb and oz are avoirdupois, not troy.
• t = 1,000 kg (metric ton).

Limits

• No stone, no hundredweight, no short/long ton as a single option.
• No newton ↔ kilogram conversion (g would be missing).
• A “weight” scale in lb shows a mass if it is calibrated that way; it is not a dynamometer.

75 kg ≈ 165.35 lb is for reading a US notice or equipment limit. For luggage, airlines round their own way: stick to their unit. Do not multiply kg by 2.2 in your head if you need the legal factor: 2.2 is a shortcut (1/0.45359237 ≈ 2.2046226).

• Treating the result as a force (newtons).

  1 kg is not 9.81 N. Here, 1 kg stays 1 kg, wherever you are on Earth.

• Taking the tonne for a short ton (about 907.185 kg).

  t = 1,000 kg. Rebuild the short ton via 2,000 lb.

• Confusing avoirdupois ounce and troy ounce (gold, silver).

  The troy ounce is not in the list. Gold does not convert with avoirdupois oz.

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Written by Rédaction HexaCalc (editorial team). Content last updated: August 25, 2026. No third-party medical or financial review is claimed.

• NIST Guide to the SI, Appendix B: Conversion Factors — National Institute of Standards and Technology
• The International System of Units (SI) — Bureau international des poids et mesures (BIPM)