The formula to calculate the mass in kilograms (kg) from milliliters (ml) is:
\[ kg = \frac{ml \cdot d}{1000} \]
Where:
Let's say the volume (ml) is 1000 milliliters and the density (d) is 1 g/ml. Using the formula:
\[ kg = \frac{1000 \cdot 1}{1000} \]
We get:
\[ kg = 1 \, \text{kg} \]
So, the mass is 1 kilogram.