Fibre Content Estimate Calculator

Work out fibre content estimate instantly with clear inputs, formula shown and shareable results.

About Fibre Content Estimate Calculator

Enzymatic-gravimetric dietary fibre is the dried indigestible residue after enzymatic digestion, corrected by subtracting the ash and residual protein it contains. Without those corrections the figure is overstated, sometimes by 10-20% of the result on mineral-rich or high-protein samples.

Formula

Dietary fibre

Fibre % = (residue - ash in residue - protein in residue) x 100 / sample weight

Worked example

With the default values below, Fibre Content Estimate Calculator returns Dietary Fibre Content of 7.5000%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Sample Weightminimum 0 g: 2 g
Dried Residue Weightminimum 0 g: 0.18 g
Ash In Residueminimum 0 g: 0.02 g
Protein In Residueminimum 0 g: 0.01 g

Results

Dietary Fibre Content: 7.5000%
Gross Residue: 9.0000%
Ash And Protein Correction: 1.5000%
Fibre Per 30 g Serving: 2.2500

Step by step

1Values used
2Dietary fibre
3Dietary Fibre Content= 7.5000
4Gross Residue= 9.0000
5Ash And Protein Correction= 1.5000
6Fibre Per 30 g Serving= 2.2500

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Does this method capture soluble fibre?

Only if the method precipitates it with ethanol before filtration, as AOAC 991.43 does. Simpler crude fibre methods measure only lignin and cellulose and greatly understate total dietary fibre.

Why do labelling figures differ from crude fibre?

Crude fibre is an old feed-analysis method that dissolves most soluble fibre and hemicellulose. Dietary fibre for labelling must use an AOAC total dietary fibre method.