If you type in a formula, you'll always have a formula. What you want to do, most likely, is create a row with the formulas, select and copy those cells, then select a new row you want to paste them in, right click and select "Paste Special...". It'll give you a dialog box. Click the "Values" radio button and then click "OK". You'll have a new row with the new values.

You can then delete the old rows and replace the original data with the new data in the new row.