A Healthy Weight Range: Common Mistakes, Tips and FAQs

Updated · Health and fitness

Introduction

Health numbers are useful when you understand what they measure and what they don't. Many popular formulas are estimates with real limits.

This article covers the most common mistakes people make with a Healthy Weight Range, what really moves the result, and answers to the questions we hear most often.

Why it matters

Understanding your figures can help you set sensible fitness goals, track change over time and know when to ask a health professional for advice.

How it's calculated

We use the NHS healthy BMI range of 18.5 to 24.9 and work backwards from your height to a weight range.

What changes the result most

The result depends on the choices you make in the calculator, so it's worth trying several combinations. In a typical example, healthy range is 56.7–76.3 kg.

Common mistakes to avoid

  1. Treating a single number as a complete picture of health.
  2. Using formulas designed for adults to assess children.
  3. Measuring inconsistently, such as at different times of day.
  4. Changing diet or exercise drastically based on one estimate.

A quick example

With the inputs below, healthy range comes out at 56.7–76.3 kg.

InputValue
Height175 cm

Tips

  • The NHS uses BMI as a screening tool, but waist measurement also matters.
  • Estimates like BMR and body fat can vary by 5–10% from lab measurements.
  • Track trends over weeks rather than day-to-day changes.
  • Speak to your GP or midwife about any results that worry you.

Frequently asked questions

What's the quickest way to work out a Healthy Weight Range?

Use our free healthy Weight Range Calculator. It applies this method automatically: We use the NHS healthy BMI range of 18.5 to 24.9 and work backwards from your height to a weight range.

Is this medical advice?

No. These tools give general estimates. For medical advice, speak to your GP, pharmacist or NHS 111.

Can I use these for children?

No. Children's BMI and health measures use age- and sex-specific charts. Use the NHS healthy weight calculator for children.

Why use stone and pounds?

Many people in the UK still think in stone and pounds, so we accept those units and show metric too.

Related calculators

Try the healthy Weight Range Calculator

Enter your own figures and get an instant answer – free, no sign-up.

Open the healthy Weight Range Calculator

For the full method, read How to Calculate a Healthy Weight Range in the UK: Step-by-Step Guide.

More health and fitness guides

This guide is general information, not financial, tax, legal or medical advice. Figures use 2025/26 UK rates where relevant. Always check GOV.UK or NHS.uk for official guidance.