# Percent of previous value

The percent of previous value gives you the percent of a value compared to the value in the row above it.

Here's an example of a percent of previous value calculation:

And here's the SQL that was used to generate it:

`${pages.page_view_count} * 100 / `

LAG(${pages.page_view_count}) OVER(ORDER BY ${pages.date_day}, ${pages.path})

In general, the SQL used for calculating the percent of the previous value has two bits (with an optional third bit):

`column_I_want_to_compare`

- this is the column with the values you want to compare`column_I_want_to_order_by`

- this is the column you want to use to order the values you want to compare`optional_other_column_I_want_to_order_by`

- this column is optional and you can add as many more`order by`

columns as you need. Normally, you'll need to add every dimension in your results table to the`ORDER BY`

bit in your SQL. And, the order of these will need to be the same as the ordering you've added to the columns in your results table.

### ๐ Here's the SQL you can copy-paste to calculate the percent of the previous valueโ

`${table.column_i_want_to_compare} * 100 / `

LAG(${table.column_i_want_to_compare}) OVER(

ORDER BY

${table.column_I_want_to_order_by},

${table.optional_other_column_I_want_to_order_by}

)

info

**๐ Level up your SQL**:

- You can round your table calculation to only show a certain number of decimal points. Here's an example where I only show two decimal points:

`ROUND(`

${table.column_i_want_to_compare} * 100 /

LAG(${table.column_i_want_to_compare}) OVER(

ORDER BY

${table.column_I_want_to_order_by},

${table.optional_other_column_I_want_to_order_by})

, 2)