# Black Scholes model

I am looking to program the Black Scholes model, but I don't understand how to write this equation as basic math.

### Example values

• Type: Put
• StockPrice: 19
• StrikePrice: 20
• YearsToMaturity: 0.16
• RiskFreeRate: 0.10
• Volatility: 0.60

I can get all of these inputs, but I just need to program the basic calculation, like (these are just made up numbers and equations)

f = a + (b/c);
f * f = z;
z / 3 + ( f * a ) = m;

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Espen Haug, the guy famous for his book on option formulas, implements Black Scholes in several languages/platforms here.

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Perfect ! thank you – Kirk Strobeck Feb 28 '12 at 17:51

This can be done very very easily in Excel. All you're doing is:

$C_t = S_t N(d_1) - N(d_2) K e^{-r(T-t)}$

where $d_1$ and $d_2$ are constants obtained through elementary calculations, $N(.)$ is the NormSdist function in Excel, and $S$, $K$ and $e^{-r(T-t)}$ are also easy to compute.

This is for a call; but it's almost the same thing as for a put.

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