What this checker works out
This checker adds the fibre in your breakfast, lunch, dinner and snacks to produce a daily total, and compares it against the adult target of around 30 g.
Building the total from meals rather than entering one figure makes it obvious where the fibre is coming from — and, usually, which meal is contributing almost none.
Enter your details
Before you fill it in
- Take figures from food labels, which show fibre per 100 g and per portion, or from a tracking app.
- Use a typical day. A single unusually good day tells you little about your usual pattern.
- Include drinks and anything eaten between meals in the snacks field.
- The 30 g target applies to adults. Children need less, rising with age.
Breakfast often contributes the least fibre and is the most habitual meal, which makes it the simplest to change permanently. A wholegrain cereal with fruit can contribute 8 to 10 g on its own — a third of the daily target before the day has properly started.
How this calculator works
A straightforward total:
Daily fibre = breakfast + lunch + dinner + snacks
Compared against the adult target of around 30 g a dayThe comparison is against a single fixed adult figure. If you need a different target — for a child, or one given by a dietitian — the Fibre Intake Calculator has an editable target and shows the shortfall across a period.
Worked example: a typical day
Using the default figures — 5 g at breakfast, 8 g at lunch, 10 g at dinner and 4 g from snacks:
- Daily total: 5 + 8 + 10 + 4 = 27 g
- This is below the adult target of around 30 g
Three grams short, and the breakdown shows where to find it. Breakfast at 5 g is the weakest meal by a clear margin; moving from a low-fibre cereal to porridge with berries would add 4 to 5 g and take the day past the target without touching anything else. Seeing the shape of the day is what makes that obvious.
Common mistakes
- Estimating from memory. Fibre content varies enormously between similar-looking products; check labels.
- Forgetting snacks. Nuts, fruit and popcorn contribute meaningfully and are easy to overlook.
- Choosing an unrepresentative day. Use a typical one.
- Assuming a high total means a good diet. Fibre is one measure among many.
- Aiming to jump straight to 30 g. Increase gradually, with more fluid.
Frequently asked questions
How do I find the fibre content of what I eat?
Packaged foods list fibre per 100 g and usually per portion in the nutrition table. For unpackaged foods, the McCance and Widdowson composition tables underpin most UK food databases and are the source behind reputable tracking apps. Rough figures are adequate here — the aim is to find the weak meal, not to audit the day precisely.
Which foods are highest in fibre?
Pulses lead comfortably: a portion of beans or lentils contributes 5 to 8 g. Wholegrain cereals and breads, nuts and seeds, and vegetables and fruit eaten with skins on are the other main contributors. Bran-based cereals are highest per 100 g, though portion sizes are small.
Should I use a fibre supplement?
Food first, in almost all cases. Supplements deliver isolated fibre without the vitamins, minerals and plant compounds that come with fibre-rich foods, and they cost more than the swaps that would achieve the same thing. Supplements have a role where a clinician has recommended one.
Is more than 30 g a problem?
For most healthy adults, no — many populations habitually eat considerably more. Very high intakes can cause discomfort if fluid intake is low, and can aggravate some gut conditions, but there is no general upper limit to worry about.
Is what I enter stored?
No. Meal figures are processed in your browser and never transmitted or retained. If thinking about food or eating is causing you distress, tracking intake against a target may make that harder rather than easier. Beat, the UK eating disorder charity, runs a free helpline and online support, and a GP can refer you to specialist services.
Related tools
References
- NHS — fibre recommendations for adults and children
- GOV.UK — Scientific Advisory Committee on Nutrition guidance on dietary fibre
Sources are checked at publication and can change — how I choose and check references.