<span>The doubling time is the period of time
required for a quantity to double in size or value. It is applied to
population growth, inflation, resource extraction, consumption of goods,
compound interest, the volume of malignant tumours, and many other
things that tend to grow over time.</span>
Doubling time<span> is the amount of </span>time<span> it takes for a given quantity to </span>double<span> in size or value at a constant growth rate. We can find the </span>doubling time<span> for a population undergoing exponential growth by using the Rule of 70. To do this, we divide 70 by the growth rate (r).
