# Brian Tracy 1000% Productivity Formula?

Hi I recently watched a Brian Tracy productivity video and I am curious about the maths behind this, I understand compound interest well but I cannot seem to get the numbers working for me.

How does Brian get the 1004%? The problem is:

If you become one tenth of one percent more productive each day, five days per week, at the end of one week you will be one half of one percent more productive (1/10 x 5 = .5%). At the end of four weeks, you will be two percent more productive (4 x .5% = 2%). At the end of fifty-two weeks, you will be 26% more productive than you were at the beginning of the year (13 x 2% =26%) or (52 weeks * 0.5% a week).

By becoming 26% more productive over the course of a year, and continuing to improve by one tenth of one percent per day, five days a week, you will actually double your overall productivity, performance and output in 2.7 years.

If you continue learning, growing and becoming more effective and efficient, an improvement of 26% per year, compounded over ten years, will result in an increase of 1004% in your overall productivity in one decade.

• I couldnt find a "compound interest" tag Commented Jul 11, 2014 at 11:35
• Do not expect perfect mathematics in statements like these. There seems to be some confusion among percent and percentages. Commented Jul 11, 2014 at 11:46
• Are you getting close to 1004% with your calculations? Commented Jul 11, 2014 at 11:47

I think all he did was take 26% increase in one year, and compound it over 10 years.

So, $$1.26^{10} = 10.09$$ 10.09 can be thought of as a 909% increase, which is *somewhere around what he said.

If you want to get slightly more detailed, you can compound it per day

$$1.001^{5*52*10} = 13.44$$

The $26\%$ a year improvement is fairly simple: $0.1\%\times 5 \times 52$. If it had been compound growth then it would be higher as $1.001^{5 \times 52} \approx 1.297$

The $2.7$ years for doubling looks wrong as $1.26^{2.7}\approx 1.866$ while $1.26^{3}\approx 2$. Perhaps it came from applying the "rule of 72" or "rule of 70" as approximations.

Compounding $26\%$ over ten years gives $1.26^{10}\approx 10.086$ which is about ten times. This is not a $1004\%$ increase, but nearer to a $909\%$ increase.