Every calculator on this site is free, works instantly in your browser, and is aligned with NHS guidance. No sign-up, no email, no app required. Pick the one you need below.

01 — BMI & healthy weight

Body Mass Index is the most widely used screening tool for weight categories. These calculators give you your BMI and what it means in NHS terms — including the important limitations.

BMI
BMI Calculator UK
Your BMI in metric or imperial — NHS-aligned categories.
BMI
Healthy BMI for Women
NHS ranges, ethnicity adjustments and the limitations every woman should know.
Ideal Weight
Ideal Weight for Height
Healthy weight ranges in stones and pounds for every UK adult height.
Healthy Weight
How Much Should I Weigh?
Healthy weight ranges by height in stones and kg, with waist measurement guidance.

02 — Calories & weight loss

Whether you're trying to lose, gain or maintain, these calculators give you the numbers — how many calories to eat, what deficit to run, and how it all fits together.

Calories
Calorie Calculator UK
Daily calorie target based on your height, weight, age and activity level.
Weight Loss
Calorie Deficit Explained
How big your deficit should be — and what happens if you go too low.
Weight Loss
Calories to Lose Weight
The 500–600 kcal deficit explained with daily targets for UK men and women.
Weight Loss
Lose 1lb a Week
The simple maths and the realistic plan that actually works long-term.
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03 — BMR & metabolism

Your Basal Metabolic Rate is the foundation of any nutrition plan. These guides explain what it is, how to calculate it, and how it relates to TDEE.

BMR
BMR Calculator
Your basal metabolic rate — calories burned at complete rest.
BMR
What Is BMR?
Plain-English guide to basal metabolic rate and how to use it.
BMR / TDEE
TDEE vs BMR
Which acronym to use for weight loss, gain, or maintenance.

04 — Macros & nutrition

Macros
Macro Calculator UK
Protein, fat and carb targets from your TDEE.
Protein
Protein Per Day UK
BHF and NHS-backed protein targets for health, weight loss and muscle.
Protein
Best Protein Sources UK
Ranked by protein per 100g and cost per gram.
Fibre
Fibremaxxing UK
Hit 30g of fibre a day without the bloat.

05 — Hydration & exercise

Water
Water Intake Calculator
Your personalised daily fluid target, NHS-aligned.
Walking
Calories Burned Walking
Realistic calorie figures by weight, pace and duration.
Walking
30 Minute Walk Calories
Exactly how many calories a 30-minute walk burns for your weight.
Walking
10,000 Steps Calories
How many calories 10,000 steps actually burns.