Convert grams to tonnes

One gram is 0.000001 tonnes. To convert any amount, multiply by 0.000001. Going the other way, one tonne is 1000000 grams.

Multiply the gram figure by 0.000001. So t = g × 0.000001. For a quick mental estimate, dividing by about 1000000 gets you close enough for most everyday purposes.

One gram is about the mass of a paperclip. The gram is the unit of nutrition labels and recipes worldwide, and of postal rates in most of the metric world.

One tonne is a small car. The tonne — metric ton — is exactly 1,000 kilograms. It differs from the US short ton (907 kg) and the UK long ton (1,016 kg), which is a genuine source of freight errors.

No. The tonne, or metric ton, is exactly 1,000 kilograms — about 2,205 pounds. The US short ton is 2,000 pounds, roughly 907 kg, and the UK long ton is 2,240 pounds, roughly 1,016 kg. The three differ by up to 12%, which is a genuine and expensive source of error in freight and construction. If a document just says "ton", find out which one it means.

Yes. Since the 1959 international yard and pound agreement, the imperial and metric systems are related by exact definitions rather than measurements — the inch is exactly 25.4 mm and the pound exactly 0.45359237 kg. Everything derived from those, including this conversion, is therefore exact. Round at the end rather than partway through, since rounding g before converting introduces an error the conversion then multiplies.