General estimate
Fibre Intake Guide
Provides an age- and sex-based general fibre reference.
How this estimate is calculated
Adequate Intake references: 38 g/day for men and 25 g/day for women up to age 50, then 30 g and 21 g respectively.
How to use the result
Treat it as a starting point to compare against how you actually feel and what you actually eat. Estimates are most useful for spotting a large gap, not for chasing a precise number.
What this cannot tell you
Increase fibre gradually and with fluid. Some digestive conditions call for a temporarily lower or differently structured fibre intake.
Estimates, not measurements: this tool runs a population equation, so it describes a typical person with your inputs rather than measuring you. Where a number drives a decision about a diagnosed condition or medication, have a dietitian or clinician sanity-check it against your history.