Schnur Scale Calculator

Estimates body surface area (DuBois method) and the Schnur sliding‑scale minimum resection weight per breast.

Patient height

What is their weight in pounds?

Body surface area (DuBois) —

Schnur scale — grams per breast —

This patient’s BSA falls outside the original 1991 Schnur study’s published range (1.35–2.55 m²). This figure is a mathematical extrapolation of the published curve, not a directly published data point — confirm against the specific payer’s policy before relying on it.

Calculated in your browser only; no patient information is transmitted or stored. Result reflects the 22nd percentile line of the Schnur sliding scale and is a clinical reference only, not a substitute for the payer’s own medical policy.

Understanding the Schnur Scale

If you are considering breast reduction surgery, your insurance company may use the Schnur Sliding Scale as one guideline for deciding whether the procedure qualifies as medically necessary.

The Schnur Scale comes from a 1991 study of 600 women who had breast reduction surgery. Researchers compared the amount of tissue removed, relative to each woman’s body size, with her reason for seeking surgery. Women who had more tissue removed for their body size consistently sought surgery for medical reasons, such as neck, back, and shoulder pain, rather than cosmetic ones. Insurance companies later adopted this relationship as a benchmark for coverage.

How it works: Your height and weight are used to calculate your body surface area (BSA) with the DuBois formula. The Schnur Scale then uses your BSA to estimate the minimum amount of breast tissue, in grams, that would need to be removed from each breast to meet this guideline.

Use this calculator to determine:

Your estimated body surface area (BSA) based on your height and weight
The estimated minimum amount of breast tissue that may need to be removed from each breast

Schnur Scale Guidelines

Body Surface Area (m²)	Minimum Tissue Per Breast
1.35	199 g
1.40	218 g
1.45	238 g
1.50	260 g
1.55	284 g
1.60	310 g
1.65	338 g
1.70	370 g
1.75	404 g
1.80	441 g
1.85	482 g
1.90	527 g
1.95	575 g
2.00	628 g
2.05	687 g
2.10	750 g
2.15	819 g
2.20	895 g
2.25	978 g
2.30	1,068 g
2.35	1,167 g
2.40	1,275 g
2.45	1,393 g
2.50 or greater	1,522+ g

Values shown reflect the 22nd percentile threshold, the version most commonly used by insurers.

For example: if your calculated BSA is 1.80 m², the Schnur Scale estimates that at least about 441 grams of tissue would need to be removed from each breast to meet this guideline.

Not All Insurers Use the Same Threshold

Insurance companies apply the Schnur Scale in different ways:

22nd percentile: Many insurers use this threshold, which is shown in the table above.
5th percentile: Some insurers use this lower threshold, which requires less tissue to be removed for a given body size.
Fixed weight: Some insurers skip the Schnur Scale and require a set minimum amount of tissue per breast, no matter your body size.

Check with your insurance company to find out which standard your plan uses.

Please Keep in Mind

The Schnur Scale is only a screening guideline and does not determine whether breast reduction surgery is medically appropriate for you. It does not take your individual symptoms or medical history into account.

Insurance requirements vary by provider and plan. Your insurance company may use different thresholds and may require more documentation, such as records of your symptoms, treatments you’ve tried, or other medical information.

The amount of tissue in the table is an estimate. Insurers may review the actual weight of the tissue removed, as recorded by the pathology lab after surgery, when making a final coverage decision.

Your surgeon and insurance provider can help determine whether your procedure meets the specific requirements of your plan.