Free calculators

Every one of them is free, ad-free and works without an account. Each number you get here comes from the same formula the FitDex app uses, so installing it doesn't mean starting over.

Your nutrition

Calorie calculatorEnter your height, weight, age and activity level to see your daily calorie needs, basal metabolic rate and macro split in seconds. The same formula as the FitDex app.
Macro calculatorTurn your daily calorie target into grams of protein, carbohydrate and fat. We publish the ratio we use and why we chose it, instead of offering preset templates with no explanation.
Water intake calculatorWork out your daily water need from your weight. We also trace where the "eight glasses a day" rule came from and why it's been misread — the real indicator isn't a glass count, it's the colour of your urine.
Food swap calculatorWhat do you gain by replacing something you eat with a lighter alternative at the same weight? 80 foods, computed at your own portion. The difference: it marks the swaps that cut calories without cutting protein and fibre.
Cups to grams converterCups, spoons, slices, handfuls — all converted to grams and calories. The difference: every food is computed with its own density, because a cup is a volume, not a weight. The same 200 ml glass holds 6.6 g of popcorn and 282 g of honey.
Recipe calorie calculatorEnter the ingredients, get the calories and macros per serving. The difference: it also shows which ingredient brings which share of the calories. In the sample recipe the olive oil is 2.6% of the weight but 15.3% of the calories.
Meal plate builderEnter a calorie target and a protein floor, get the grams for all four zones of the plate. It runs backwards: you give the total, the tool solves the grams. It also shows how much room is left for the grain when you change the protein source.
Nutrition label analyzerEnter the table from the back of the pack and get which claims the product may legally carry, the traffic-light colour of four nutrients, and whether the label is internally consistent. In the sample product three lights are red, yet it qualifies for exactly one claim: low salt.
Caffeine calculatorEnter what you drank today and when you go to bed, and see how much caffeine is still in you at lights out. In the sample day the total is 268 mg — under the daily limit — and 64 mg is still there at bedtime.
Protein intake calculatorWork out your daily protein target in grams per kilo and see whether it fits your meals. In the sample body the target is 164 g; split across three meals that is 55 g per meal, against a saturation ceiling of 33 g.

Your body

Your plan

Artificial intelligence

Food photo calorie calculatorSee what the small gap left by eyeballing your plate instead of photographing it adds up to over weeks: how many calories a day, how many kilos by the end, and how much of it correction gives back.