Change prices by % across the board

Is there currently a way to do this? We have to adjust prices often due to the fluctuating market and would like an easy way to change our product prices by percentage eg. add 15% to all prices of a certain category or across the board?

Create a Promotion.

Goto your admin - catalog - promotions

Click on Add catalog promotion. Under Conditions click add condition. Select Categories or your option.

Then continue to select the Categories of your choice if it's all of them then select all of them.

Then go to Bonuses and select by or to percentage of the original price then put in your 15 for 15%…

This is just an example. Hope this helps.

catalog, products, global update.