In "one up on wall street", Peter Lynch has talked about PEG ratio, PE ratio, Growth rates on many occasions. Though the PEG definition is simple i.e. PE/Sustainable Future Growth rate, calculating the same is not simple as it depends on sustainable future growth rate.

According to him, the most important factors that affect future growth rates are:
1]Cost reduction
2]expansion into new markets
3]raising of prices
4]selling of more products
5]closing/revitalizing a losing operation.

Since the estimated future growth rate varies from one analyst to other, it is difficult have one value for PEG ratio. I use the consensus estimate given by Rueters.com to arrive at PEG.

However small companies like Hawkins or zydus, we don't get eps estimates on Reuters. TEDies can share their way of how they find PEG especially for smaller companies.

is there any site /s which gives historical PE ratios for stocks

Basant Sir,

To find PEG ratio, should we use:

1] PEG = TTMPE/ Projected 3 year growth rate

or

2] PEG = TTMPE/ (ROE (1-DPR))

where ROE and DPR are estimated from latest Financial Year results (past).

or

3]PEG = TTMPE/ (ROE (1-DPR))

where ROE and DPR are estimated for current Financial Year  (projected).

And the projected growth rate,is an educated guess by studying the business dynamics?
May be thats why investing is an art not a science.

Sir can PEG be applied to stocks from all sectors?
If not what are the exceptions?
Banks?