Hi everyone, I have one sizing question: estimating the yearly sales of electric toothbrushes in China (including the yearly sales of the toothbrush Heads)
This is how I did:
1. To calculate the sales of electric toothbrushes
Chinese population: 1400m; assume the number of people in each age group is evenly distributed.
1400m/4 = 350m
Therefore, there are 140 m people having electric toothbrushes in China
each has one toothbrush
Replacement rate 1/3 (life = 3 years)
Growth rate 20%
the yearly sales = 140m*1*(1/3+20%) = 75m
However, I have stuck in the calculation of the yearly sales of the toothbrush heads:
I assumed that each newly bought electric toothbrush has 4 heads, and each head can be used for 1 quarter.
Can anyone help me with that? Thanks :)