There are a few things you can do to speed up large worksheets in Excel:

1. Use the built-in calculation options to automatically recalculate formulas as you type.
2. Manually calculate formulas by pressing F9, or by selecting the formulas you want to calculate, and then pressing F9.
3. Use array formulas to perform multiple calculations with a single formula.
4. Use conditional formatting to highlight cells that meet certain criteria.
5. Filter data to view only the rows or columns that you want to see.

1. Use the built-in calculation options to automatically recalculate formulas as you type.

In Excel, you can set the calculation options to automatically recalculate formulas as you type. To do this, go to File > Options > Formulas. Under "Calculation options", select "Automatic". This will cause Excel to automatically recalculate formulas as you type.

2. Manually calculate formulas by pressing F9, or by selecting the formulas you want to calculate, and then pressing F9.