How formulas are calculated in Excel?

[The Recruiter]

I have done the basic things of an Excel including the formulas. Now I am eager to know the logic of the calculations that are performed in MS Excel. I want to know that how to calculate formulas are made in different versions of Microsoft Excel. So thought to ask you people, since you explain properly in simple language.!! So please explain me how formulas are calculated in Excel?

[chroma]

In versions of Excel earlier than Excel 2002, calculation formulas are made on a leaf by leaf, starting with Sheet1 in your Excel workbook. After the calculations are completed in Sheet1, Excel calculates the formulas on Sheet2 sheet until all the formulas are calculated on all sheets in your workbook. This process works well as antecedents and are dependent on the same sheet. If the background and are dependent on different leaves, but leaf external references, this can cause problems.

[Bigga Lexx]

I think that you can understand the logic more better if you have a look at the following example :
If the formula in Sheet1 A1 is = Sheet3 A4 + 1, both Sheet1 A1 and Sheet3 A4 does calculation. Start with the worksheet "Sheet1". When you try to calculate A1, you can not achieve because Sheet3 A4 has not yet calculated. More you can try calculating in Sheet1. When you are finished with Sheet1, Sheet2 calculate the sheet. Then calculate Sheet3, last updated Sheet3 A4.
At this point, you press all the leaves. However, Sheet1 A1 still has not been calculated, then go above and start calculating Sheet1 again. Finally, Sheet1 A1 can be calculated. You loop over all the leaves want to calculate an arbitrary number of times, depending on the number sheet inter-dependencies are and how they are presented.

[ThoMas321]

In Excel 2002 and Excel 2003, a big list of history is preserved formulas for calculations. That is to say, all the formulas that are contained in your workbook are placed in memory as a continuous list of formulas. When you enter a new formula and it is fully determined for the first time it is placed in its correct location in the chain of calculation. Excel starts the task of calculation formulas from the top of the list. If a previous formula was calculated, Excel returns the list of formulas and calculates the formula dependent. Excel returns the formula and then finishes the previous calculation.

[Sam.D]

Excel 2007 makes calculations of formulas as a set of functions. To optimize performance, all functions are aggregated into as few queries as possible. These requests are usually aggregated executed in the background when other Excel functions are inactive. In aggregated queries, a big list of history is preserved formulas for calculations. All functions are contained in your workbook are placed in memory as a continuous list of functions. When you enter a new formula in a workbook, the new formula is then calculated for the first time. When the new formula is calculated for the first time, Excel 2007 generates a set of functions that belong to the new formula, and then each function in the feature set is placed in its correct location in the chain of calculation.

[Zenon]

As the string calculation is being processed, each cell is evaluated. If a cell has no dependency on another function, the cell receives its value immediately. If the cell has a dependency on another function, the cell receives an error value placeholder # GETTING_DATA and then proceeds to calculate the next cell in the chain. Once all cells have been evaluated once, Excel 2007 triggers aggregation query or queries to extract necessary data. While the aggregate or requests are processed, cell awaiting data continues to display the error value placeholder # GETTING_DATA.