Free Health Tools

BMI Calculator

Instantly calculate your BMI and understand what the result means — and what it doesn’t — for your health.

Understanding Your BMI — And What It Means for Your Health

Is my BMI Good or Bad - and what should i do next?

Why does BMI sometimes give 'Wrong' results?

How do i turn my BMI into a daily calories & protein target:

Fettle turns nutrition science into a practical system that adapts week by week - helping you eat better, stay consistent, and make progress without overthinking or obsessing over every meal.

Instead of rigid plans or constant manual tracking, Fettle guides decisions upfront and adjusts as your body, habits, and goals change over time.

Interpreting BMI

Understanding Your BMI - And What It Means For Your Health

Fettle turns nutrition science into a practical system that adapts week by week - helping you eat better, stay consistent, and make progress without overthinking or obsessing over every meal.

Instead of rigid plans or constant manual tracking, Fettle guides decisions upfront and adjusts as your body, habits, and goals change over time.

Is my BMI Good or Bad - and what should i do next?

Why does BMI sometimes give 'Wrong' results?

How do i turn my BMI into a daily calories & protein target:

Daily Nutrition Targets

Calculating your Personal Daily Calorie & Protein Targets

Using your height, weight, age, and activity level, we estimate your Total Daily Energy Expenditure (TDEE) — the calories your body needs each day.

TDEE Calculator

Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a day.

Protein Calculator
Daily Protein Targets

Protein needs vary by body weight, goal and activity - not one-size-fits-all-rules.

This is a LOT to calculate - and it changes over time depending on your goal.

Fettle updates these targets automatically, based on your weight, activity, goals, and weekly progress.

Why Thousands Trust Fettle

Doing your own calculations is the #1 reason people fail.

Fettle updates them automatically - every single week.

Science-Backed Calculations

Most calorie calculators use outdated formulas or oversimplified numbers.

Fettle uses a clinically validated method designed by a registered nutritionist - the same approach used by professionals working with athletes and weight-loss patients.

  • Adjusts for body fat %, not just height and weight

  • Calculate minimum safe fats, proteins and carbs

  • Re-checks metabolic data every week

Weekly Personalisation

Your body changes - your calories should too.

Every 7 days, Fettle analyses your check-in data (weight, waist, hips, activity) and automatically adjusts your calories and macro targets. No guesswork. No manual maths. No confusion.

  • Accounts for plateaus and metabolic slowdown.

  • Prevents overeating or under-eating.

  • Designed for long-term sustainable results.

Real-Life Usability

You don't live inside a spreadsheet - and your nutrition plan shouldn't feel like one.

Fettle gives you simple meal plans, quick swaps, realistic recipes, and a shopping list that fits your actual lifestyle.

  • Recipes based on your taste preferences.

  • Amazon Fresh Integration (Others coming soon).

  • Works whether you cook daily or rely on quick meals.

Science-Backed Calculations

Most calorie calculators use outdated formulas or oversimplified numbers.

Fettle uses a clinically validated method designed by a registered nutritionist - the same approach used by professionals working with athletes and weight-loss patients.

  • Adjusts for body fat %, not just height and weight

  • Calculate minimum safe fats, proteins and carbs

  • Re-checks metabolic data every week

Weekly Personalisation

Your body changes - your calories should too.

Every 7 days, Fettle analyses your check-in data (weight, waist, hips, activity) and automatically adjusts your calories and macro targets. No guesswork. No manual maths. No confusion.

  • Accounts for plateaus and metabolic slowdown.

  • Prevents overeating or under-eating.

  • Designed for long-term sustainable results.

Real-Life Usability

You don't live inside a spreadsheet - and your nutrition plan shouldn't feel like one.

Fettle gives you simple meal plans, quick swaps, realistic recipes, and a shopping list that fits your actual lifestyle.

  • Recipes based on your taste preferences.

  • Amazon Fresh Integration (Others coming soon).

  • Works whether you cook daily or rely on quick meals.

Science-Backed Calculations

Most calorie calculators use outdated formulas or oversimplified numbers.

Fettle uses a clinically validated method designed by a registered nutritionist - the same approach used by professionals working with athletes and weight-loss patients.

  • Adjusts for body fat %, not just height and weight

  • Calculate minimum safe fats, proteins and carbs

  • Re-checks metabolic data every week

Weekly Personalisation

Your body changes - your calories should too.

Every 7 days, Fettle analyses your check-in data (weight, waist, hips, activity) and automatically adjusts your calories and macro targets. No guesswork. No manual maths. No confusion.

  • Accounts for plateaus and metabolic slowdown.

  • Prevents overeating or under-eating.

  • Designed for long-term sustainable results.

Real-Life Usability

You don't live inside a spreadsheet - and your nutrition plan shouldn't feel like one.

Fettle gives you simple meal plans, quick swaps, realistic recipes, and a shopping list that fits your actual lifestyle.

  • Recipes based on your taste preferences.

  • Amazon Fresh Integration (Others coming soon).

  • Works whether you cook daily or rely on quick meals.

Loved by Real People

Accountant

“Fettle finally made healthy eating doable. I’m a busy dad and this is the first app I’ve actually stuck to.”

@mark_j

Busy Professional

iOS User

“The weekly check-ins helped me lose 4kg in six weeks. No stress, no calorie obsession — just simple guidance.”

@sophie.fit

Weight Loss Progress

Mum of 2

“I love that it lets me follow my macros while still eating Chinese food. My parents couldn’t believe an app finally understands our cuisine!”

@kelly_lau

Cultural Fit

Stop guessing. Start progressing.

Free to try. No commitment. No Spam.

Join the Beta

Guidance First, Tracking Second

A different way to approach nutrition

Most nutrition apps ask you to log everything first — then leave the hard decisions to you.

Fettle works the other way around.

We help you understand how much to eat, what fits your targets, and how to plan for real life, so tracking becomes a tool for refinement — not pressure, guilt, or guesswork.

This is nutrition designed to guide decisions upfront, adapt over time, and support progress without punishment.

How much to eat

Fettle calculates your calorie and macro targets using evidence-based formulas — then updates them as your body, activity, and goals change.

You start with clarity, not guesswork.

What fits your target

Meals are matched to your targets — not the other way around.

Fettle helps you choose foods and portions that fit your goals and preferences, without rigid rules or food anxiety.

How to plan for real life

From meal ideas to shopping lists, Fettle helps you plan in a way that works outside the app.

So staying on track feels practical, flexible, and sustainable — even on busy weeks.

Your Nutrition Superpower

How Fettle Works

Your personalised plan is built in minutes - and adapts every week based on your results.

How Much To Eat

Fettle calculates your calorie and macro targets using evidence-based formulas — then updates them as your body, activity, and goals change.

You start with clarity, not guesswork.

How Much To Eat

Fettle calculates your calorie and macro targets using evidence-based formulas — then updates them as your body, activity, and goals change.

You start with clarity, not guesswork.

What Fits Your Targets

Meals are matched to your targets — not the other way around.

Fettle helps you choose foods and portions that fit your goals and preferences, without rigid rules or food anxiety.

What Fits Your Targets

Meals are matched to your targets — not the other way around.

Fettle helps you choose foods and portions that fit your goals and preferences, without rigid rules or food anxiety.

How To Plan For Real Life

Fettle turns your plan into action — from meals to shopping.

Meals you choose are organised into a weekly shopping list, so staying on track doesn’t rely on memory, willpower, or extra admin.

How To Plan For Real Life

Fettle turns your plan into action — from meals to shopping.

Meals you choose are organised into a weekly shopping list, so staying on track doesn’t rely on memory, willpower, or extra admin.

Quick answers

How Accurate is the Calorie Calculation?

How Much Does Fettle Cost?

Is Fettle a Replacement for a Nutritionist or Coach?

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