Convert kilometres to centimetres

One kilometre is 100000 centimetres. To convert any amount, multiply by 100000. Going the other way, one centimetre is 0.00001 kilometres.

Multiply the kilometre figure by 100000. So cm = km × 100000. For a quick mental estimate, multiplying by about 100000 gets you within a percent or so, which is close enough for most everyday purposes.

One kilometre is about a 12-minute walk. The kilometre is the standard road-distance unit everywhere except the United States, the United Kingdom and a handful of small territories.

One centimetre is about the width of an adult fingernail. The centimetre is the everyday metric unit for body measurements and paper sizes, though it is not an SI-preferred prefix step — engineers tend to jump from millimetres to metres.

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 km before converting introduces an error the conversion then multiplies.