Free health calculators that explain the answer

BMI calculator: adult BMI and reference chart

Calculate adult BMI in metric, pounds or stone, see height-specific reference points, and understand the result's limits. Free, private and evidence-based.

Original diagram of a drink beside caffeine milligrams divided by matching drink volume in millilitres, multiplied by 100 to give mg per 100 ml.

Caffeine per 100 ml calculator

Convert matching labelled caffeine milligrams and drink volume in millilitres into mg per 100 ml. Free, private concentration arithmetic with no safe-dose verdict.

Worked food-label example: 150 kcal in 30 g becomes 500 kcal per 100 g.

Calories per 100 g calculator

Convert calories and gram weight from the same labelled portion into kcal per 100 g. Free calculator with a worked example, label checks and no intake target.

Calories per meal calculator

Split a daily calorie or kilojoule amount equally or by your own percentages. Whole-number meal results always add back to your exact total.

Daily calorie needs calculator: energy requirement and resting estimate

Estimate adult daily energy with the 2023 DRI equation and see a separate Mifflin–St Jeor resting estimate in kcal and kJ.

Example label arithmetic: 4 g fibre divided by a matching 28 g reference gives 14.3% after rounding; this is not a personal target.

Percent Daily Value calculator

Calculate a nutrient amount as a percentage of a supplied Daily Value. Check matching units and servings, with clear examples and no account required.

Two clocks joined by a day-to-night timing arc beside an empty plate

Fasting window calculator

Calculate the exact time between your last and next calories, or work out when a fasting window ends. Neutral clock arithmetic with no protocol advice.

Invented food-label example: 6 g dietary fiber and 200 kcal from one serving equals 3.00 g fiber per 100 kcal.

Fiber per 100 calories calculator

Calculate dietary fiber per 100 calories from matching food-label values. Compare the ratio, see worked examples and understand its limits. Free and private.

One US fluid ounce is 29.57 mL and one Imperial fluid ounce is 28.41 mL after rounding; volume units are kept distinct from mass.

Fluid ounces to mL converter

Convert US or Imperial fluid ounces to millilitres and back. Choose the correct system, see exact factors and understand food-label rounding differences.

Worked grocery example: a pack price of 3.60 and weight of 300 g gives 1.20 per 100 g in the same currency.

Grocery unit price calculator

Convert a grocery pack price and net weight into price per 100 g. Compare the same currency and weight basis, with clear examples and no account required.

Kilograms to pounds converter

Convert one body-weight or training-weight value between kilograms (kg) and international avoirdupois pounds (lb), without judging the weight or calculating a dose.

Kilojoules to calories converter

Convert food energy between kilojoules (kJ) and kilocalories (kcal) using the exact 4.184 factor, with clear units and private on-device calculation.

Invented package example: price 30 and total labelled protein 600 g give a cost of 1.25 in the same currency per 25 g of protein.

Protein cost calculator

Compare price per 25 g of labelled protein from a matching package or serving price and protein amount. See examples, currency limits and private local calculations.

Invented food-label example: 20 g protein and 200 kcal in the same serving gives 10.00 g protein per 100 kcal.

Protein per 100 calories calculator

Calculate grams of protein per 100 calories from matching food-label values. See worked examples, serving-size checks and clear limits, with no account required.

Bowls of chickpeas beside a kitchen scale and a card reading Protein per 100 g; no protein quantity is shown.

Protein per 100 g calculator

Convert protein grams per serving and matching solid-food serving weight into grams of protein per 100 g. Free, private label arithmetic.

A recipe scaled from two to six portions: 250 grams of an ingredient becomes 750 grams.

Recipe scaling calculator

Scale one ingredient quantity from a recipe's original servings to the number of servings you want. Exact ratio arithmetic with no hidden unit conversion.

Illustrative nutrition-label diagram: 3 g saturated fat in 30 g food scales to 10 g per 100 g. This is a synthetic example, not a real product or dietary target.

Saturated Fat per 100 g Calculator

Convert saturated fat in a matching food serving to grams per 100 g. Compare like labels with exact arithmetic, clear limits and no personal dietary target.

Illustrated nutrition label with sodium and serving mass fields leading to a sodium-per-100-gram comparison; no food value is shown.

Sodium per 100 g calculator

Convert labelled sodium per serving and its matching serving weight to milligrams per 100 g. Compare like foods on a common basis. Free and private.

Sodium to salt converter

Convert food-label sodium in milligrams to salt equivalent in grams, or salt grams back to sodium, using the standard 2.5 factor.

Diagram of total sugars and serving size from one food label leading to a per 100 g comparison; no food result is shown.

Total sugar per 100 g calculator

Convert labelled total sugars per serving and matching serving weight into grams per 100 g. Compare like foods on a common basis. Free and private.

Waist-to-height ratio calculator (WHtR)

Calculate your waist-to-height ratio and equivalent percentage in centimetres or inches. See careful measurement guidance and limitations without a risk label.

Waist-to-hip ratio calculator (WHR)

Calculate an adult waist-to-hip ratio in centimetres or inches, with clear tape-measure guidance, uncertainty and no automatic health-risk label.

Weight loss percentage calculator

Calculate weight change as a percentage of your starting weight. See the amount and whether the current value is lower, higher or unchanged.