fiber a day for a 2,000 calorie diet.
Also look for foods with added bran or other sources of fiber. Read labels when comparing brands and choose the one that provides the most fiber.
Finally, keep in mind that you’ll likely need to make some food swaps to meet fiber intake goals without adding more daily calories than you need in the process.
More information
The Linus Pauling Institute at Oregon State University has more on fiber and the richest sources.