Units from the metric system can be used to describe the mass, volume or length of an object. Mass is measured in grams (g) and kilograms (kg). Volume is measured in millilitres (ml) and litres (l).

When comparing or combining an area or volume it is important to measure the objects using the same units. Without converting the areas into the same unit, it might be difficult to tell, for example, ...

We've explained dozens of times over the years the difference between P-metric and imperial tire sizes so we won't cover a whole lot of the same ground, but we really haven't published a conversion ...

Your cheat sheet for converting min/mile to min/km – and what paces you need to run to hit your 5K, 10K, half marathon and marathon targets ...