Tonne

A thousand kilograms — the freight-and-industry unit.

Mass

How it's defined

Exactly 1,000 kg (sometimes "metric ton" in the US, where the 2,000-pound "short ton" also exists — a classic unit trap).

1 t = 1,000 kg — exact1 US short ton = 907.18474 kg — exact, and different

Convert — honestly

t equals

1000 kg

Kilogram · factor exact — the base unit itself

1000000 g

Gram · factor exact — exact by definition

2204.62262 lb

Pound · factor exact — exact by the 1959 agreement

6.0221e+29 u

Atomic mass unit · factor measured — measured (CODATA), carries uncertainty

Conversions run through the kilogram using the stated factors — no rounding beyond display precision, and every factor says whether it's exact or measured.

Where you meet it

Shipping, CO₂ emission figures, and truck limits
Wastii-to-be — waste streams weigh in

Other ways to measure mass

kg Kilogram g Gram lb Pound u Atomic mass unit

Source

This page is an authored summary of the authoritative definition — checkable one click away.

NIST Special Publication 811 — Guide for the Use of the SI