HEALTH & EVERYDAY
Body fat calculator
Estimate body-fat percentage using the US Navy circumference method.
What this calculator does
Estimate body-fat percentage using the US Navy circumference method.. It is designed to answer the common UK search intent for this topic with the key assumptions shown clearly.
Estimated result
- Method
- US Navy female circumference formula
- Measurement system
- Centimetres converted to inches internally
A circumference-based estimate, not a clinical measurement. Measure consistently and do not use the result as a diagnosis.
SOURCES & REVIEW
Checked against official guidance
Last reviewed 14 July 2026 · Rule version GB-2026.27.1
Daily/weekly source monitoring. If a source changes, the affected rule set is reviewed before publication.
All source links are kept visible so you can verify the figures used on this page.
NHS: Healthy weight ↗Sources, methodology and update policy →Report an issue or correction →WHY RESULTS DIFFER
Why two users can see different results
Why the result can differ
Different tax codes, payroll periods, Scottish bands, pension methods or lender assumptions can change the outcome.
One-off bonuses, pay frequency, overpayments, allowances and reliefs can move the result away from a simple annual estimate.
Where a rule depends on eligibility or legal status, this page shows an estimate and links to official guidance.
This section is intentionally repeated on key tools so the explanation stays near the result instead of being hidden in a separate policy page.
COMMON QUESTIONS
Frequently asked questions
Is this an exact quote or tax return?
No. It is an estimate based on the inputs and assumptions shown.
When was this checked?
The method and linked official guidance were reviewed for the current UK release.