Waist‑to‑Hip Ratio
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Interpretation

Ratio {{ (+ratio).toFixed(Math.max(0, Math.floor(+decimals||0))) }} indicates {{ classification }} risk by {{ use_custom ? 'Custom' : 'WHO' }} cut‑offs.


                
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Introduction:

Waist to hip ratio is a simple indicator of body fat distribution and central adiposity. It helps you understand whether more fat is carried around the waist compared with the hips, a pattern often linked with higher cardiometabolic risk. Many clinicians use this measure alongside weight and height based indices to add context.

You enter waist and hip circumferences and choose units, then the ratio is calculated and placed into a sex specific band that describes relative risk. A typical use is tracking changes after training or diet adjustments, since the number can shift even when weight changes slowly. One example is a waist of 80 to hip of 100 which yields a ratio of 0.80 and sits near the moderate band for women, so small measurement errors can change the label.

Measure consistently at standard landmarks and relax the abdomen for a natural exhale so the tape sits level. For the waist use the midpoint between the lower rib and the top of the hip bone, and for the hip use the widest part of the buttocks keeping the tape parallel to the floor. Repeating the measure twice and averaging can reduce noise.

Results guide conversations and everyday choices, not diagnoses. This tool provides informational estimates and does not substitute professional advice.

Technical Details:

The quantity measured is the waist to hip ratio, abbreviated WHR. Inputs are circumferences of waist and hip reported in centimetres or inches. The computation is a snapshot that compares two girth measures taken at standard landmarks after a normal exhale.

The index is calculated by dividing waist circumference by hip circumference. A larger value indicates more central fat relative to hip girth. Interpretation uses three bands labeled Low, Moderate, and High, with thresholds that differ by sex. Custom cutoffs can replace the defaults when a specific study or protocol is preferred.

Values near band borders deserve caution, since small tape placement shifts or rounding choices can move a result from one band to the next. Comparisons are most valid within the same person over time using the same method and unit choice.

r = W H
Symbols and units used in the calculation
Symbol Meaning Unit/Datatype Source
W Waist circumference at midpoint between lower rib and iliac crest after normal exhale cm or in Input
H Hip circumference at widest buttock level, tape parallel to floor cm or in Input
r Waist to hip ratio Number Derived
Worked example.
W = 80cm H = 100cm r = 80 100 =0.80

For a woman, 0.80 sits at the border of Moderate risk; a small change may shift the band.

Default interpretation bands by sex
Sex Threshold Band Lower Bound Upper Bound Interpretation
Male Low 0 < 0.90 Lower central adiposity pattern
Male Moderate 0.90 < 1.00 Intermediate pattern
Male High ≥ 1.00 Higher central adiposity pattern
Female Low 0 < 0.80 Lower central adiposity pattern
Female Moderate 0.80 < 0.85 Intermediate pattern
Female High ≥ 0.85 Higher central adiposity pattern
  • Unit conversion uses 1 in = 2.54 cm. Ratio is computed in centimetres.
  • Display rounding is selectable from 0 to 4 decimals; the internal ratio keeps up to 4 decimals.
  • Custom bands use A and B where Low < A, Moderate < B, else High. A and B must be positive and A < B.
  • A gauge visualizes the value with dynamic max scaled to the high cutoff plus margin.
Validation rules and bounds
Field Type Min Max Step/Pattern Error Text
Waist circumference Number 0 native number
Hip circumference Number 0 native number
Sex Male or Female select
Rounding (decimals) Integer 0 4 step 1
Use custom cutoffs Boolean switch
Custom cutoff A Number 0 step 0.01
Custom cutoff B Number 0 step 0.01

I/O summary. Inputs are two numeric girths and one sex selection; outputs are the ratio, a band label, a table summary, a gauge, and optional CSV or JSON downloads. Identical inputs yield identical outputs.

Units and rounding. The decimal separator is a dot. Conversions to centimetres use one decimal in displays. The ratio display follows the selected decimal count.

Privacy & compliance. Processing occurs on the device; no data is transmitted or stored server side. Health related outputs are informational only.

Assumptions & limitations

  • Heads‑up Band thresholds are adult oriented and may not apply to youth or pregnancy.
  • Muscular or athletic builds can yield higher ratios without excess fat.
  • Single time point measures do not capture day to day variability.
  • Tape tension and placement are major sources of error.
  • Different studies may propose other cutoffs; defaults reflect a common public health scheme.
  • Inches are converted to centimetres before calculation; rounding can shift borders.
  • Custom cutoffs require A < B and both positive; invalid settings fall back to defaults.
  • Gauge scaling is approximate and intended for orientation rather than precise reading.

Edge cases & error sources

  • Zero or missing waist or hip produces no ratio.
  • Very small hips relative to waist inflate the ratio and may exceed the gauge scale.
  • Non numeric input is ignored by the native number control.
  • Trailing spaces or symbols are not accepted by the number control.
  • Extreme values can reduce readability of the gauge axis.
  • Changing decimals alters only display precision, not the internal cut decisions.
  • Unit changes trigger conversion; rounding to one decimal may hide tiny shifts.
  • Copying values to CSV or JSON does not change internal precision.
  • Rapid toggling of tabs defers chart drawing until the chart tab is active.
  • Browser floating point quirks can affect edge rounding at two decimals.

Step‑by‑Step Guide:

Measure waist and hip, then interpret the waist to hip ratio against the appropriate band.

  1. Choose Sex to apply the correct thresholds.
  2. Enter Waist at the midpoint after a normal exhale.
  3. Enter Hip at the widest buttock level.
  4. Select Units in cm or in.
  5. Adjust Decimals for display precision.
  6. Optionally enable Custom cutoffs and set A and B.

Example: Sex = Female, Waist = 80 cm, Hip = 100 cm, Decimals = 2 → WHR 0.80, Moderate band.

  • Keep the tape level and snug but not compressing soft tissue.

FAQ:

Is my data stored?

No. Calculations occur on your device and no measurements are sent to a server.

Use local device security when saving CSV or JSON.
How accurate is the result?

Accuracy depends on tape placement, relaxation, and unit choice. Repeat measures and average for stability near band borders.

Which units are supported?

Centimetres and inches are accepted. Inputs in inches are converted to centimetres before computing the ratio.

Can I define my own cutoffs?

Yes. Turn on custom cutoffs and set A and B where A is the Low to Moderate border and B is the Moderate to High border.

What does a borderline result mean?

It is close to a threshold. Recheck placement and repeat the measures. Small differences can switch the band label.

Does it work without connectivity?

Yes after the page is loaded. The computation itself does not require a network connection.

Is there a cost or license to consider?

The calculator is provided for informational use. Check the site’s terms for licensing details.

Troubleshooting:

  • No result shown → ensure both waist and hip are positive numbers.
  • Wrong unit → switch units and reenter values as needed.
  • Band seems off → verify the correct sex is selected.
  • Values copy oddly → confirm your spreadsheet expects a dot as the decimal separator.
  • Chart missing → open the gauge tab to trigger drawing.
  • Custom cutoffs ignored → ensure A and B are positive and A is less than B.

Advanced Tips:

Tip Take two readings for each site and average to smooth hand variation.

Tip Record the same time of day to improve comparability across weeks.

Tip Keep the tape horizontal in a mirror to reduce tilt error.

Tip Use centimetres when possible to reduce rounding jumps near borders.

Tip Track the same landmarks across sessions for consistent W and H.

Tip Add notes about training or diet changes alongside each entry.

Glossary:

Waist circumference (W)
Tape girth at the midpoint after a normal exhale.
Hip circumference (H)
Tape girth at the widest buttock level.
Waist to hip ratio (r)
Dimensionless index computed as W divided by H.
Centimetre (cm)
Length unit; base unit used for calculation.
Inch (in)
Imperial length unit; converted to centimetres.
Cutoff
Threshold that separates risk bands for interpretation.