It is very easy to calculate the value of a pip in terms of the quote currency (the right-hand currency of the pair).
If you work with standard lots (lots of 100,000 units), 1 pip equals 10 untis of the quote currency or 1,000 yen (if you're trading JPY).
If you work with mini lots (lots of 10,000 units), one pip equals 1 unit of the quote currency. The exception would be JPY - 1 pip is 100 yen.
If you work with micro lots (lots of 1,000 units), 1 pip equals 0.10 units of the quote currency or 10 yen (if you're trading JPY).
For example: you buy/sell 10,000 USD/CHF, so every pip equals 1 Swiss franc. If you buy/sell 230,450 EUR/USD, 1 pip equals 23.45 US dollars (NOT 23.45 euro).
If you want to calculate the pip value in terms of the base currency, the calculation gets slightly tougher. Here's an example:
Let's assume that you open a 1-minilot position ($10,000).
USD/CHF at an exchange rate of 1.0352 (0.0001 / 1.0352) х $10 000 = 0.97 US dollars per pip.
GBP / JPY at an exchange rate of 148.59 (0.01 / 148.59) х GBP 10 000 = 0.67 GBP per pip.